diff --git a/web/src/components/common/ImagePreview.tsx b/web/src/components/common/ImagePreview.tsx
new file mode 100644
index 0000000..0710139
--- /dev/null
+++ b/web/src/components/common/ImagePreview.tsx
@@ -0,0 +1,121 @@
+import { useEffect, useCallback, useState, type MouseEvent } from 'react'
+import { createPortal } from 'react-dom'
+import { CloseOutlined, DownloadOutlined, ZoomInOutlined } from '@ant-design/icons'
+
+export interface ImagePreviewProps {
+  open: boolean
+  src: string
+  alt?: string
+  onClose: () => void
+}
+
+/**
+ * 通用大图预览：遮罩 + 居中大图，支持 ESC / 点遮罩关闭，可下载。
+ */
+export function ImagePreview({ open, src, alt = '图片预览', onClose }: ImagePreviewProps) {
+  const onKey = useCallback((e: KeyboardEvent) => {
+    if (e.key === 'Escape') onClose()
+  }, [onClose])
+
+  useEffect(() => {
+    if (!open) return
+    document.addEventListener('keydown', onKey)
+    const prev = document.body.style.overflow
+    document.body.style.overflow = 'hidden'
+    return () => {
+      document.removeEventListener('keydown', onKey)
+      document.body.style.overflow = prev
+    }
+  }, [open, onKey])
+
+  if (!open || !src) return null
+
+  const stop = (e: MouseEvent) => e.stopPropagation()
+
+  const download = () => {
+    const a = document.createElement('a')
+    a.href = src
+    a.download = alt || 'image'
+    a.target = '_blank'
+    a.rel = 'noopener noreferrer'
+    a.click()
+  }
+
+  const node = (
+    <div
+      className="fixed inset-0 z-[2000] flex items-center justify-center bg-black/75 p-4 sm:p-8"
+      onClick={onClose}
+      role="dialog"
+      aria-modal="true"
+      aria-label={alt}
+    >
+      <div className="absolute top-4 right-4 flex items-center gap-2 z-10">
+        <button
+          type="button"
+          onClick={e => { stop(e); download() }}
+          className="w-9 h-9 rounded-full bg-white/15 hover:bg-white/25 text-white flex items-center justify-center border-0 cursor-pointer"
+          title="下载 / 新窗口打开"
+        >
+          <DownloadOutlined />
+        </button>
+        <button
+          type="button"
+          onClick={e => { stop(e); onClose() }}
+          className="w-9 h-9 rounded-full bg-white/15 hover:bg-white/25 text-white flex items-center justify-center border-0 cursor-pointer"
+          title="关闭"
+        >
+          <CloseOutlined />
+        </button>
+      </div>
+      <img
+        src={src}
+        alt={alt}
+        onClick={stop}
+        className="max-w-full max-h-[min(90vh,900px)] object-contain rounded-lg shadow-2xl select-none"
+        draggable={false}
+      />
+    </div>
+  )
+
+  return createPortal(node, document.body)
+}
+
+export interface ChatImageProps {
+  src: string
+  alt?: string
+  /** 缩略图样式 */
+  className?: string
+}
+
+/**
+ * 聊天内可点击图片：缩略图 + 通用 ImagePreview
+ */
+export function ChatImage({ src, alt = '聊天图片', className = '' }: ChatImageProps) {
+  const [open, setOpen] = useState(false)
+
+  if (!src) return null
+
+  return (
+    <>
+      <button
+        type="button"
+        className="p-0 m-0 border-0 bg-transparent cursor-zoom-in block text-left relative group max-w-full"
+        onClick={() => setOpen(true)}
+        title="点击预览"
+      >
+        <img
+          src={src}
+          alt={alt}
+          className={`rounded-lg block object-cover ${className}`}
+          loading="lazy"
+        />
+        <span className="pointer-events-none absolute inset-0 rounded-lg bg-black/0 group-hover:bg-black/15 transition-colors flex items-center justify-center">
+          <ZoomInOutlined className="text-white text-lg opacity-0 group-hover:opacity-90 drop-shadow" />
+        </span>
+      </button>
+      <ImagePreview open={open} src={src} alt={alt} onClose={() => setOpen(false)} />
+    </>
+  )
+}
+
+export default ImagePreview
diff --git a/web/src/pages/agent/ChatHistory.tsx b/web/src/pages/agent/ChatHistory.tsx
index 53388b0..8225b6c 100644
--- a/web/src/pages/agent/ChatHistory.tsx
+++ b/web/src/pages/agent/ChatHistory.tsx
@@ -5,6 +5,7 @@ import {
   getCustomers, getSession, getSessions,
   type Customer, type Message, type Session, type SessionEvent,
 } from '@/services/api'
+import { ChatImage } from '@/components/common/ImagePreview'
 
 const statusColors: Record<string, string> = {
   active: 'blue', waiting: 'orange', ended: 'green', archived: 'default',
@@ -212,7 +213,7 @@ const ChatHistory = () => {
                           {isAgent ? '客服' : '访客'}
                         </div>
                         {message.type === 'image' ? (
-                          <img src={message.content} alt="图片" className="max-w-56 max-h-56 rounded-lg" />
+                          <ChatImage src={message.content} alt="图片" className="max-w-56 max-h-56" />
                         ) : (
                           <div className="whitespace-pre-wrap break-words">{message.content}</div>
                         )}
diff --git a/web/src/pages/agent/Dashboard.tsx b/web/src/pages/agent/Dashboard.tsx
index 177cf29..445cf26 100644
--- a/web/src/pages/agent/Dashboard.tsx
+++ b/web/src/pages/agent/Dashboard.tsx
@@ -6,6 +6,7 @@ import {
   ExportOutlined, BookOutlined, PictureOutlined,
 } from '@ant-design/icons'
 import EmojiPicker, { insertAtCursor } from '@/components/common/EmojiPicker'
+import { ChatImage } from '@/components/common/ImagePreview'
 import { useAuth } from '@/stores/auth'
 import {
   addSessionNote, claimSession, endSession, getAvailableAgents, getCustomers, getKnowledgeEntries,
@@ -725,7 +726,7 @@ const Dashboard = () => {
                             }`}
                           >
                             {message.type === 'image' ? (
-                              <img src={message.content} alt="聊天图片" className="max-w-64 max-h-64 rounded-lg" />
+                              <ChatImage src={message.content} alt="聊天图片" className="max-w-64 max-h-64" />
                             ) : (
                               <p className="text-sm leading-normal whitespace-pre-wrap break-words m-0">{message.content}</p>
                             )}
diff --git a/web/src/widgets/VisitorChat.tsx b/web/src/widgets/VisitorChat.tsx
index 6cae776..28672a9 100644
--- a/web/src/widgets/VisitorChat.tsx
+++ b/web/src/widgets/VisitorChat.tsx
@@ -4,6 +4,7 @@ import {
   StarFilled, MinusOutlined, PictureOutlined, CustomerServiceOutlined,
 } from '@ant-design/icons'
 import EmojiPicker, { insertAtCursor } from '@/components/common/EmojiPicker'
+import { ChatImage } from '@/components/common/ImagePreview'
 
 interface Message {
   id: number
@@ -468,7 +469,7 @@ const VisitorChat = ({
             <div key={msg.id} className="flex justify-end max-w-[85%] ml-auto">
               <div className={`rounded-xl bg-[#2563eb] text-white text-[13px] leading-normal ${msg.type === 'image' ? 'p-1.5' : 'px-4 py-3'}`}>
                 {msg.type === 'image' ? (
-                  <img src={msg.content} alt="图片" className="max-w-[180px] rounded-lg block" />
+                  <ChatImage src={msg.content} alt="图片" className="max-w-[180px] max-h-[180px]" />
                 ) : (
                   <p className="m-0 whitespace-pre-wrap break-words">{msg.content}</p>
                 )}
@@ -481,7 +482,7 @@ const VisitorChat = ({
               </div>
               <div className={`rounded-xl bg-white border border-neutral-200 text-[13px] text-neutral-800 leading-normal ${msg.type === 'image' ? 'p-1.5' : 'px-4 py-3'}`}>
                 {msg.type === 'image' ? (
-                  <img src={msg.content} alt="图片" className="max-w-[180px] rounded-lg block" />
+                  <ChatImage src={msg.content} alt="图片" className="max-w-[180px] max-h-[180px]" />
                 ) : (
                   <p className="m-0 whitespace-pre-wrap break-words">{msg.content}</p>
                 )}