diff --git a/tests/test_user_deletion.py b/tests/test_user_deletion.py
new file mode 100644
index 0000000..392823a
--- /dev/null
+++ b/tests/test_user_deletion.py
@@ -0,0 +1,99 @@
+import os
+import unittest
+from types import SimpleNamespace
+
+os.environ.setdefault("DATABASE_URL", "sqlite://")
+os.environ.setdefault("APP_ENCRYPTION_KEY", "MDEyMzQ1Njc4OWFiY2RlZjAxMjM0NTY3ODlhYmNkZWY=")
+
+from sqlalchemy import create_engine, event
+from sqlalchemy.orm import sessionmaker
+
+from web.backend.database import Base
+from web.backend.models import Account, AuditLog, LoginTask, User
+from web.backend.routers.users import delete_user, list_users, rename_user
+from web.backend.schemas import UserRename
+
+
+class UserDeletionTests(unittest.TestCase):
+    def setUp(self):
+        self.engine = create_engine("sqlite://")
+
+        @event.listens_for(self.engine, "connect")
+        def enable_foreign_keys(connection, _):
+            connection.execute("PRAGMA foreign_keys=ON")
+
+        Base.metadata.create_all(self.engine)
+        self.session = sessionmaker(bind=self.engine)()
+        self.admin = User(username="admin", password_hash="hash", role="super_admin")
+        self.user = User(username="support", password_hash="hash", role="support")
+        self.session.add_all([self.admin, self.user])
+        self.session.commit()
+        self.session.add(Account(
+            username="douyu-user",
+            password="password",
+            email="mail@example.com",
+            email_password="mail-password",
+            assigned_to=self.user.id,
+        ))
+        self.session.commit()
+        account = self.session.query(Account).one()
+        self.session.add(LoginTask(
+            batch_id="batch-1",
+            account_id=account.id,
+            created_by=self.user.id,
+        ))
+        self.session.commit()
+
+    def tearDown(self):
+        self.session.close()
+        Base.metadata.drop_all(self.engine)
+        self.engine.dispose()
+
+    def test_delete_user_soft_deletes_and_releases_assigned_accounts(self):
+        result = delete_user(
+            self.user.id,
+            db=self.session,
+            current=SimpleNamespace(id=self.admin.id, username=self.admin.username),
+        )
+
+        deleted = self.session.get(User, self.user.id)
+        account = self.session.query(Account).one()
+        self.assertTrue(result["success"])
+        self.assertEqual(result["released_accounts"], 1)
+        self.assertFalse(deleted.is_active)
+        self.assertIsNotNone(deleted.deleted_at)
+        self.assertEqual(deleted.deleted_username, "support")
+        self.assertTrue(deleted.username.startswith(f"deleted-{deleted.id}-"))
+        self.assertIsNone(account.assigned_to)
+        self.assertEqual(self.session.query(AuditLog).one().target, "support")
+        self.assertEqual(self.session.query(LoginTask).one().created_by, deleted.id)
+        self.assertEqual([item.id for item in list_users(db=self.session)], [self.admin.id])
+
+    def test_cannot_delete_current_user(self):
+        with self.assertRaisesRegex(Exception, "不能删除当前登录用户"):
+            delete_user(
+                self.user.id,
+                db=self.session,
+                current=SimpleNamespace(id=self.user.id, username=self.user.username),
+            )
+
+    def test_rename_preserves_user_id_and_related_data(self):
+        result = rename_user(
+            self.user.id,
+            UserRename(username="renamed-support"),
+            db=self.session,
+            current=SimpleNamespace(id=self.admin.id, username=self.admin.username),
+        )
+
+        renamed = self.session.get(User, self.user.id)
+        account = self.session.query(Account).one()
+        task = self.session.query(LoginTask).one()
+        self.assertEqual(result.username, "renamed-support")
+        self.assertEqual(renamed.id, self.user.id)
+        self.assertEqual(account.assigned_to, self.user.id)
+        self.assertEqual(task.created_by, self.user.id)
+        self.assertEqual(self.session.query(AuditLog).one().target, "support -> renamed-support")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/web/backend/migrations/versions/20260813_0023_soft_delete_users.py b/web/backend/migrations/versions/20260813_0023_soft_delete_users.py
new file mode 100644
index 0000000..cf8ad5b
--- /dev/null
+++ b/web/backend/migrations/versions/20260813_0023_soft_delete_users.py
@@ -0,0 +1,36 @@
+"""支持用户软删除并保留历史任务归属"""
+
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision: str = "20260813_0023"
+down_revision: Union[str, None] = "20260812_0022"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def _columns(bind, table_name: str) -> set[str]:
+    return {column["name"] for column in sa.inspect(bind).get_columns(table_name)}
+
+
+def upgrade() -> None:
+    bind = op.get_bind()
+    columns = _columns(bind, "users")
+    if "deleted_at" not in columns:
+        op.add_column("users", sa.Column("deleted_at", sa.DateTime(), nullable=True))
+        op.create_index("ix_users_deleted_at", "users", ["deleted_at"])
+    if "deleted_username" not in columns:
+        op.add_column("users", sa.Column("deleted_username", sa.String(length=64), nullable=True))
+
+
+def downgrade() -> None:
+    bind = op.get_bind()
+    columns = _columns(bind, "users")
+    if "deleted_username" in columns:
+        op.drop_column("users", "deleted_username")
+    if "deleted_at" in columns:
+        op.drop_index("ix_users_deleted_at", table_name="users")
+        op.drop_column("users", "deleted_at")
diff --git a/web/backend/models.py b/web/backend/models.py
index c9ef83a..c4273e1 100644
--- a/web/backend/models.py
+++ b/web/backend/models.py
@@ -34,6 +34,8 @@ class User(Base):
     custom_permissions = Column(JSON, nullable=True, comment="自定义权限列表，null表示使用角色默认权限")
     created_at = Column(DateTime, default=_utcnow)
     updated_at = Column(DateTime, default=_utcnow, onupdate=_utcnow)
+    deleted_at = Column(DateTime, nullable=True, index=True)
+    deleted_username = Column(String(64), default="")
 
     # 客服被分配的账号
     assigned_accounts = relationship("Account", back_populates="assigned_user", foreign_keys="Account.assigned_to")
diff --git a/web/backend/permissions.py b/web/backend/permissions.py
index b5ba135..2a9ae51 100644
--- a/web/backend/permissions.py
+++ b/web/backend/permissions.py
@@ -6,6 +6,7 @@ PERMISSIONS = {
     "user:view": "查看用户列表",
     "user:create": "创建用户",
     "user:edit": "编辑用户",
+    "user:rename": "修改用户名",
     "user:delete": "删除用户",
     "user:assign_permissions": "分配权限",
     # 账号管理
diff --git a/web/backend/routers/users.py b/web/backend/routers/users.py
index a1a5ea3..0f54e22 100644
--- a/web/backend/routers/users.py
+++ b/web/backend/routers/users.py
@@ -1,14 +1,18 @@
 """用户管理路由（超管）"""
 
+from datetime import datetime, timezone
+from uuid import uuid4
+
 from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import Session
 
 from ..database import get_db
-from ..models import User, AuditLog
+from ..models import Account, AuditLog, HuyaAccount, User
 from ..security import hash_password
-from ..permissions import ROLE_LABELS, PERMISSIONS, get_user_permissions
-from ..schemas import UserCreate, UserUpdate, UserInfo
-from ..deps import require_permission, get_current_user
+from ..permissions import PERMISSIONS, get_user_permissions
+from ..schemas import UserCreate, UserRename, UserUpdate, UserInfo
+from ..deps import require_permission
 
 router = APIRouter(prefix="/api/users", tags=["用户管理"])
 
@@ -18,7 +22,7 @@ def list_users(
     db: Session = Depends(get_db),
     _: User = Depends(require_permission("user:view")),
 ):
-    users = db.query(User).order_by(User.id).all()
+    users = db.query(User).filter(User.deleted_at.is_(None)).order_by(User.id).all()
     result = []
     for u in users:
         result.append(UserInfo(
@@ -76,6 +80,8 @@ def update_user(
     user = db.query(User).filter(User.id == user_id).first()
     if not user:
         raise HTTPException(status_code=404, detail="用户不存在")
+    if user.deleted_at is not None:
+        raise HTTPException(status_code=404, detail="用户不存在")
 
     if req.password:
         user.password_hash = hash_password(req.password)
@@ -103,6 +109,51 @@ def update_user(
     )
 
 
+@router.patch("/{user_id}/username", response_model=UserInfo)
+def rename_user(
+    user_id: int,
+    req: UserRename,
+    db: Session = Depends(get_db),
+    current: User = Depends(require_permission("user:rename")),
+):
+    """仅变更用户名，保留用户 ID 和全部关联业务数据。"""
+    user = db.query(User).filter(User.id == user_id, User.deleted_at.is_(None)).first()
+    if not user:
+        raise HTTPException(status_code=404, detail="用户不存在")
+
+    username = req.username.strip()
+    if len(username) < 2:
+        raise HTTPException(status_code=400, detail="用户名至少 2 个字符")
+    if username == user.username:
+        return UserInfo(
+            id=user.id, username=user.username, role=user.role,
+            is_active=user.is_active, remark=user.remark or "",
+            permissions=get_user_permissions(user), custom_permissions=user.custom_permissions,
+        )
+    if db.query(User.id).filter(User.username == username).first():
+        raise HTTPException(status_code=400, detail="用户名已存在")
+
+    old_username = user.username
+    user.username = username
+    db.add(AuditLog(
+        user_id=current.id,
+        username=current.username,
+        action="user:rename",
+        target=f"{old_username} -> {username}",
+    ))
+    try:
+        db.commit()
+    except IntegrityError as exc:
+        db.rollback()
+        raise HTTPException(status_code=400, detail="用户名已存在") from exc
+    db.refresh(user)
+    return UserInfo(
+        id=user.id, username=user.username, role=user.role,
+        is_active=user.is_active, remark=user.remark or "",
+        permissions=get_user_permissions(user), custom_permissions=user.custom_permissions,
+    )
+
+
 @router.delete("/{user_id}")
 def delete_user(
     user_id: int,
@@ -112,14 +163,39 @@ def delete_user(
     user = db.query(User).filter(User.id == user_id).first()
     if not user:
         raise HTTPException(status_code=404, detail="用户不存在")
+    if user.deleted_at is not None:
+        raise HTTPException(status_code=404, detail="用户不存在")
     if user.role == "super_admin":
         raise HTTPException(status_code=400, detail="不能删除超级管理员")
+    if user.id == current.id:
+        raise HTTPException(status_code=400, detail="不能删除当前登录用户")
 
+    # 保留任务与审计记录的创建者 ID，避免删除用户时破坏历史数据。
+    released_accounts = (
+        db.query(Account)
+        .filter(Account.assigned_to == user.id)
+        .update({Account.assigned_to: None}, synchronize_session=False)
+    )
+    released_huya_accounts = (
+        db.query(HuyaAccount)
+        .filter(HuyaAccount.assigned_to == user.id)
+        .update({HuyaAccount.assigned_to: None}, synchronize_session=False)
+    )
+    deleted_username = user.username
     db.add(AuditLog(user_id=current.id, username=current.username,
-                    action="user:delete", target=user.username))
-    db.delete(user)
+                    action="user:delete", target=deleted_username))
+    user.is_active = False
+    user.deleted_at = datetime.now(timezone.utc)
+    user.deleted_username = deleted_username
+    # 释放用户名供新用户使用，同时不改变历史任务通过 user.id 保存的归属。
+    user.username = f"deleted-{user.id}-{uuid4().hex[:12]}"
     db.commit()
-    return {"message": "已删除", "success": True}
+    return {
+        "message": "已删除",
+        "success": True,
+        "released_accounts": released_accounts,
+        "released_huya_accounts": released_huya_accounts,
+    }
 
 
 @router.get("/permissions/list")
diff --git a/web/backend/schemas.py b/web/backend/schemas.py
index 47969e7..4e17594 100644
--- a/web/backend/schemas.py
+++ b/web/backend/schemas.py
@@ -97,6 +97,10 @@ class UserUpdate(BaseModel):
     custom_permissions: Optional[list[str]] = None
 
 
+class UserRename(BaseModel):
+    username: str = Field(..., min_length=2, max_length=64)
+
+
 # ---- 账号 ----
 class AccountImport(BaseModel):
     """批量导入，文本格式：用户名|密码|邮箱|邮箱密码|标签(可选)
diff --git a/web/frontend/src/App.tsx b/web/frontend/src/App.tsx
index df253db..2d35d3d 100644
--- a/web/frontend/src/App.tsx
+++ b/web/frontend/src/App.tsx
@@ -1,8 +1,8 @@
-import { lazy, Suspense, useState, useCallback, type ReactNode } from 'react';
+import { lazy, Suspense, useState, useCallback, useEffect, type ReactNode } from 'react';
 import { BrowserRouter, Routes, Route, Navigate } from 'react-router-dom';
 import { App as AntdApp, ConfigProvider, Spin, theme } from 'antd';
 import zhCN from 'antd/locale/zh_CN';
-import { getUser } from './store/auth';
+import { fetchCurrentUser, getUser } from './store/auth';
 import { ThemeProvider } from './store/theme';
 import { useTheme } from './store/useTheme';
 import AntdMessageBridge from './utils/AntdMessageBridge';
@@ -44,6 +44,12 @@ function AppContent() {
   const isLoggedIn = !!getUser();
   const { isDark } = useTheme();
 
+  // localStorage 仅是前端缓存；每次加载应用时以服务端的实时权限为准。
+  useEffect(() => {
+    if (!getUser()) return;
+    void fetchCurrentUser().finally(refreshAuth);
+  }, [refreshAuth]);
+
   return (
     <ConfigProvider
       locale={zhCN}
diff --git a/web/frontend/src/api/users.ts b/web/frontend/src/api/users.ts
index 6525e60..8c27428 100644
--- a/web/frontend/src/api/users.ts
+++ b/web/frontend/src/api/users.ts
@@ -7,6 +7,8 @@ export const userApi = {
     api.post<UserInfo, UserInfo>('/users', data),
   update: (id: number, data: { password?: string; role?: string; is_active?: boolean; remark?: string; custom_permissions?: string[] | null }) =>
     api.put<UserInfo, UserInfo>(`/users/${id}`, data),
+  rename: (id: number, username: string) =>
+    api.patch<UserInfo, UserInfo>(`/users/${id}/username`, { username }),
   delete: (id: number) => api.delete<MessageResponse, MessageResponse>(`/users/${id}`),
   listPermissions: () => api.get<PermissionsListResult, PermissionsListResult>('/users/permissions/list'),
 };
diff --git a/web/frontend/src/pages/UsersPage.tsx b/web/frontend/src/pages/UsersPage.tsx
index f6eb266..ac7b4ec 100644
--- a/web/frontend/src/pages/UsersPage.tsx
+++ b/web/frontend/src/pages/UsersPage.tsx
@@ -1,8 +1,9 @@
 import { useEffect, useState, useCallback } from 'react';
 import {
   Table, Button, Modal, Form, Input, Select, Tag, Popconfirm, Space,
-  Checkbox, Divider, Alert, Tooltip,
+  Checkbox, Divider, Alert,
 } from 'antd';
+import type { TableProps } from 'antd';
 import { message } from '../utils/antdMessage';
 import { PlusOutlined, EditOutlined, DeleteOutlined, SafetyOutlined } from '@ant-design/icons';
 import { userApi, type UserInfo } from '../api/modules';
@@ -61,6 +62,11 @@ export default function UsersPage() {
   const { can } = usePermissions();
 
   const canAssignPerm = can('user:assign_permissions');
+  const canCreate = can('user:create');
+  const canEdit = can('user:edit');
+  const canRename = can('user:rename');
+  const canDelete = can('user:delete');
+  const canManageUser = canEdit || canRename;
 
   const loadUsers = useCallback(async () => {
     setLoading(true);
@@ -87,6 +93,7 @@ export default function UsersPage() {
 
   const handleEdit = (user: UserInfo) => {
     setEditing(user);
+    form.resetFields();
     form.setFieldsValue({
       username: user.username,
       role: user.role,
@@ -99,9 +106,14 @@ export default function UsersPage() {
     try {
       const values = await form.validateFields();
       if (editing) {
-        const updateData: { role: string; remark: string; password?: string } = { role: values.role, remark: values.remark };
-        if (values.password) updateData.password = values.password;
-        await userApi.update(editing.id, updateData);
+        if (canRename && values.username !== editing.username) {
+          await userApi.rename(editing.id, values.username);
+        }
+        if (canEdit) {
+          const updateData: { role: string; remark: string; password?: string } = { role: values.role, remark: values.remark };
+          if (values.password) updateData.password = values.password;
+          await userApi.update(editing.id, updateData);
+        }
         message.success('已更新');
       } else {
         await userApi.create(values);
@@ -170,12 +182,13 @@ export default function UsersPage() {
     setSelectedPerms(rolePerms);
   };
 
-  const columns = [
+  const columns: TableProps<UserInfo>['columns'] = [
     { title: 'ID', dataIndex: 'id', width: 60 },
-    { title: '用户名', dataIndex: 'username' },
+    { title: '用户名', dataIndex: 'username', width: 128, ellipsis: true },
     {
       title: '角色',
       dataIndex: 'role',
+      width: 100,
       render: (role: string) => {
         const label = ROLE_OPTIONS.find((r) => r.value === role)?.label || role;
         return <Tag color={ROLE_COLORS[role] || 'default'}>{label}</Tag>;
@@ -196,21 +209,27 @@ export default function UsersPage() {
       width: 80,
       render: (active: boolean) => active ? <Tag color="green">启用</Tag> : <Tag>禁用</Tag>,
     },
-    { title: '备注', dataIndex: 'remark', ellipsis: true },
+    { title: '备注', dataIndex: 'remark', width: 180, ellipsis: true },
     {
       title: '操作',
       width: 200,
+      fixed: 'right',
+      align: 'left',
       render: (_: unknown, record: UserInfo) => (
-        <Space>
-          <Button size="small" icon={<EditOutlined />} onClick={() => handleEdit(record)}>编辑</Button>
-          {canAssignPerm && (
-            <Tooltip title="权限管理">
-              <Button size="small" icon={<SafetyOutlined />} onClick={() => handlePermClick(record)}>权限</Button>
-            </Tooltip>
+        <Space size={4} wrap={false}>
+          {canManageUser && (
+            <Button size="small" type="text" icon={<EditOutlined />} onClick={() => handleEdit(record)}>编辑</Button>
           )}
-          {record.role !== 'super_admin' && (
-            <Popconfirm title="确认删除？" onConfirm={() => handleDelete(record.id)}>
-              <Button danger size="small" icon={<DeleteOutlined />}>删除</Button>
+          {canAssignPerm && (
+            <Button size="small" type="text" icon={<SafetyOutlined />} onClick={() => handlePermClick(record)}>权限</Button>
+          )}
+          {canDelete && record.role !== 'super_admin' && (
+            <Popconfirm
+              title="确认删除该用户？"
+              description="该用户将被停用并解除账号分配，历史任务会保留。"
+              onConfirm={() => handleDelete(record.id)}
+            >
+              <Button danger size="small" type="text" icon={<DeleteOutlined />}>删除</Button>
             </Popconfirm>
           )}
         </Space>
@@ -222,7 +241,7 @@ export default function UsersPage() {
     <div>
       <div style={{ marginBottom: 16, display: 'flex', justifyContent: 'space-between' }}>
         <h2>用户管理</h2>
-        <Button type="primary" icon={<PlusOutlined />} onClick={handleCreate}>新建用户</Button>
+        {canCreate && <Button type="primary" icon={<PlusOutlined />} onClick={handleCreate}>新建用户</Button>}
       </div>
       <Table
         columns={columns}
@@ -230,6 +249,8 @@ export default function UsersPage() {
         rowKey="id"
         loading={loading}
         size="small"
+        tableLayout="fixed"
+        scroll={{ x: 844 }}
         pagination={{
           current: currentPage,
           pageSize,
@@ -252,24 +273,30 @@ export default function UsersPage() {
         open={modalOpen}
         onCancel={() => setModalOpen(false)}
         onOk={handleSave}
-        okText="保存"
+        okText={editing && !canEdit ? '保存用户名' : '保存'}
+        width={560}
       >
         <Form form={form} layout="vertical">
-          <Form.Item name="username" label="用户名" rules={[{ required: true, message: '请输入用户名' }]}>
-            <Input disabled={!!editing} />
+          <Form.Item
+            name="username"
+            label="用户名"
+            extra={editing && canRename ? '改名不会改变用户 ID，账号分配、任务、支付和审计记录均会保留。' : undefined}
+            rules={[{ required: true, message: '请输入用户名' }, { min: 2, max: 64, message: '用户名长度需为 2-64 个字符' }]}
+          >
+            <Input disabled={!!editing && !canRename} autoComplete="off" />
           </Form.Item>
           <Form.Item
             name="password"
             label={editing ? '新密码（留空不修改）' : '密码'}
             rules={editing ? [] : [{ required: true, message: '请输入密码' }]}
           >
-            <Input.Password />
+            <Input.Password disabled={!!editing && !canEdit} autoComplete="new-password" placeholder={editing ? '留空不修改' : undefined} />
           </Form.Item>
           <Form.Item name="role" label="角色" rules={[{ required: true }]}>
-            <Select options={ROLE_OPTIONS} />
+            <Select disabled={!!editing && !canEdit} options={ROLE_OPTIONS} />
           </Form.Item>
           <Form.Item name="remark" label="备注">
-            <Input />
+            <Input disabled={!!editing && !canEdit} />
           </Form.Item>
         </Form>
       </Modal>