diff --git a/apps/backend/src/repositories/kuaishou-cloud-task-state-repo.test.ts b/apps/backend/src/repositories/kuaishou-cloud-task-state-repo.test.ts
new file mode 100644
index 00000000..76b0620c
--- /dev/null
+++ b/apps/backend/src/repositories/kuaishou-cloud-task-state-repo.test.ts
@@ -0,0 +1,43 @@
+import assert from 'node:assert/strict'
+import test from 'node:test'
+
+import { syncKuaishouCloudTaskStateForTask } from './kuaishou-cloud-task-state-repo.js'
+
+test('syncKuaishouCloudTaskStateForTask 将 Date 更新时间规范化为 ISO 字符串', async () => {
+  const calls: Array<{ text: string; params?: unknown[] }> = []
+  const executor = async (text: string, params?: unknown[]) => {
+    calls.push({ text, params })
+    return { rows: [] }
+  }
+
+  await syncKuaishouCloudTaskStateForTask({
+    taskId: 9,
+    executorKey: 'kuaishou_ct_assisted',
+    contextJson: {
+      kuaishouCloudFulfillment: {
+        ticket: {
+          status: 'verified',
+          code: '597172E91CF18417',
+        },
+        binding: {
+          bindUrl: 'https://example.test/bind',
+          vnPhone: '14062706492',
+          roleName: '测试角色',
+          roleId: '4212063544',
+          resolvedSourceKey: 'account_test',
+        },
+        dispatch: {
+          status: 'pending',
+        },
+        consume: {
+          status: 'pending',
+        },
+      },
+    },
+    updatedAt: new Date('2026-05-29T09:05:46.658Z'),
+  }, executor)
+
+  assert.equal(calls.length, 1)
+  assert.match(calls[0].text, /INSERT INTO kuaishou_cloud_task_states/)
+  assert.equal(calls[0].params?.[10], '2026-05-29T09:05:46.658Z')
+})
diff --git a/apps/backend/src/repositories/kuaishou-cloud-task-state-repo.ts b/apps/backend/src/repositories/kuaishou-cloud-task-state-repo.ts
index f925899b..539e3d95 100644
--- a/apps/backend/src/repositories/kuaishou-cloud-task-state-repo.ts
+++ b/apps/backend/src/repositories/kuaishou-cloud-task-state-repo.ts
@@ -1,6 +1,7 @@
 import { query } from '../db/client.js'
 import { maskCode } from '../utils/masking.js'
 import { parseTaskContext } from '../utils/task-json.js'
+import { normalizeTimestampIso } from '../utils/time.js'
 
 type QueryExecutor = (text: string, params?: unknown[]) => Promise<{ rows: unknown[] }>
 type JsonRecord = Record<string, any>
@@ -39,7 +40,7 @@ export async function syncKuaishouCloudTaskStateForTask(
   const consume = asRecord(flow.consume)
   const roleName = pickFirstNonEmpty([role.name, binding.roleName])
   const roleId = pickFirstNonEmpty([role.rid, binding.roleId])
-  const updatedAt = String(input.updatedAt || '').trim() || new Date().toISOString()
+  const updatedAt = normalizeTimestampIso(input.updatedAt)
 
   await executor(
     `
diff --git a/apps/backend/src/repositories/task-repo.ts b/apps/backend/src/repositories/task-repo.ts
index 420e91b9..ac9fd781 100644
--- a/apps/backend/src/repositories/task-repo.ts
+++ b/apps/backend/src/repositories/task-repo.ts
@@ -2,6 +2,7 @@ import { query, withTransaction } from '../db/client.js'
 import type { PoolClient } from 'pg'
 
 import { syncKuaishouCloudTaskStateForTask } from './kuaishou-cloud-task-state-repo.js'
+import { normalizeTimestampIso } from '../utils/time.js'
 import type {
   TaskCreateInput,
   TaskListQueryInput,
@@ -245,7 +246,7 @@ export async function updateTaskStatusIfCurrent(
   currentStatus: string,
   patch: TaskUpdatePatch,
 ): Promise<TaskRow | null> {
-  const now = String(patch.updated_at || '').trim()
+  const now = normalizeTimestampIso(patch.updated_at, '')
   return withTransaction(async (client) => {
     const result = await client.query<{
       id: number
diff --git a/apps/backend/src/utils/time.ts b/apps/backend/src/utils/time.ts
index 8e5a9fac..78122d0e 100644
--- a/apps/backend/src/utils/time.ts
+++ b/apps/backend/src/utils/time.ts
@@ -6,3 +6,18 @@ export function addHours(baseIso: string | null | undefined, hours: number): str
   const baseTime = baseIso ? new Date(baseIso).getTime() : Date.now()
   return new Date(baseTime + hours * 60 * 60 * 1000).toISOString()
 }
+
+export function normalizeTimestampIso(value: unknown, fallbackIso = nowIso()): string {
+  if (value instanceof Date) {
+    const timestamp = value.getTime()
+    return Number.isFinite(timestamp) ? value.toISOString() : fallbackIso
+  }
+
+  const normalized = String(value || '').trim()
+  if (!normalized) {
+    return fallbackIso
+  }
+
+  const timestamp = Date.parse(normalized)
+  return Number.isFinite(timestamp) ? new Date(timestamp).toISOString() : fallbackIso
+}