diff --git a/front/src/App.tsx b/front/src/App.tsx
index 031d624..2b31d25 100644
--- a/front/src/App.tsx
+++ b/front/src/App.tsx
@@ -1,14 +1,15 @@
 import React, { useCallback, useEffect, useRef, useState } from 'react';
 import { BrowserRouter, Routes, Route } from 'react-router-dom';
-import { tokens, useToastController, Toast, ToastTitle } from '@fluentui/react-components';
+import { tokens, useToastController, Toast, ToastTitle, Dialog, DialogSurface, DialogBody, DialogTitle, DialogContent, DialogActions, Button, Input, Text } from '@fluentui/react-components';
 import { MainLayout } from './layouts/MainLayout';
 import About from './components/About';
 import CreatePost from './components/CreatePost';
 import PostCard from './components/PostCard';
 import ImageViewer from './components/ImageViewer';
-import { fetchArticles, type Article } from './api';
+import { fetchArticles, reset_identity_token, type Article } from './api';
 import { useLayout } from './context/LayoutContext';
 import './App.css';
+import { Eye24Regular, EyeOff24Regular, Copy24Regular } from '@fluentui/react-icons';
 
 const Home: React.FC<{ onPreviewImage: (src: string, alt?: string) => void }> = ({ onPreviewImage }) => {
   const { refreshTrigger } = useLayout();
@@ -154,6 +155,19 @@ function App() {
     setImageViewer({ open: true, src, alt });
   };
   const closeImageViewer = () => setImageViewer({ open: false });
+  const [identityDialogOpen, setIdentityDialogOpen] = useState(false);
+  const [identityToken, setIdentityToken] = useState('');
+  const [identityVisible, setIdentityVisible] = useState(false);
+
+  useEffect(() => {
+    const handler = () => {
+      setIdentityToken(localStorage.getItem('identity_token') || '');
+      setIdentityVisible(false);
+      setIdentityDialogOpen(true);
+    };
+    window.addEventListener('identity_invalid', handler as EventListener);
+    return () => window.removeEventListener('identity_invalid', handler as EventListener);
+  }, []);
 
   return (
     <BrowserRouter>
@@ -162,10 +176,70 @@ function App() {
           path="/"
           element={
             <MainLayout
-              imageViewer={
-                imageViewer.open && imageViewer.src ? (
-                  <ImageViewer src={imageViewer.src!} alt={imageViewer.alt} onClose={closeImageViewer} />
-                ) : null
+              overlays={
+                <>
+                  {imageViewer.open && imageViewer.src ? (
+                    <ImageViewer src={imageViewer.src!} alt={imageViewer.alt} onClose={closeImageViewer} />
+                  ) : null}
+                  <Dialog open={identityDialogOpen} onOpenChange={(_, data) => setIdentityDialogOpen(!!data.open)}>
+                    <DialogSurface>
+                      <DialogBody>
+                        <DialogTitle>Identity_token无效，是否重置？</DialogTitle>
+                        <DialogContent>
+                          <Text block style={{ color: tokens.colorPaletteRedForeground1 }}>
+                            注意：重置Identity_token后，你将以一个全新的匿名身份继续使用本站，你将无法再修改或删除使用旧 identity 发布的内容！
+                          </Text>
+                          <div style={{ marginTop: tokens.spacingVerticalS }}>
+                            <Text block>当前Identity_token:</Text>
+                            <div style={{ display: 'flex', gap: tokens.spacingHorizontalS, alignItems: 'center', marginTop: tokens.spacingVerticalXS }}>
+                              <Input
+                                type={identityVisible ? 'text' : 'password'}
+                                value={identityToken}
+                                readOnly
+                              />
+                              <Button
+                                appearance="secondary"
+                                icon={identityVisible ? <EyeOff24Regular /> : <Eye24Regular />}
+                                onClick={() => setIdentityVisible(v => !v)}
+                              />
+                              <Button
+                                appearance="secondary"
+                                icon={<Copy24Regular />}
+                                disabled={!identityVisible}
+                                onClick={() => {
+                                  if (!identityVisible || !identityToken) return;
+                                  navigator.clipboard.writeText(identityToken).catch(() => {});
+                                }}
+                              />
+                            </div>
+                          </div>
+                        </DialogContent>
+                        <DialogActions>
+                          <Button
+                            appearance="secondary"
+                            onClick={() => setIdentityDialogOpen(false)}
+                          >
+                            否
+                          </Button>
+                          <Button
+                            appearance="primary"
+                            onClick={async () => {
+                              try {
+                                const token = await reset_identity_token();
+                                setIdentityToken(token);
+                                setIdentityDialogOpen(false);
+                              } catch (err) {
+                                console.error('Failed to reset identity token:', err);
+                              }
+                            }}
+                          >
+                            是
+                          </Button>
+                        </DialogActions>
+                      </DialogBody>
+                    </DialogSurface>
+                  </Dialog>
+                </>
               }
             />
           }
diff --git a/front/src/api.ts b/front/src/api.ts
index d1d73a7..25373d6 100644
--- a/front/src/api.ts
+++ b/front/src/api.ts
@@ -117,6 +117,26 @@ export const get_id_token = async (): Promise<string> => {
   return token;
 };
 
+const notifyInvalidIdentity = () => {
+  if (typeof window !== 'undefined') {
+    window.dispatchEvent(new CustomEvent('identity_invalid'));
+  }
+};
+
+const handlePostApiCode = (json: any) => {
+  if (json && json.code === 2004) {
+    notifyInvalidIdentity();
+    throw new Error(json.data || 'Identity token invalid');
+  }
+};
+
+export const reset_identity_token = async (): Promise<string> => {
+  const token = await fetch_id_token();
+  localStorage.removeItem('identity_token');
+  localStorage.setItem('identity_token', token);
+  return token;
+};
+
 export interface CreatePostResponse {
     code: number;
     data: any;
@@ -156,7 +176,9 @@ export const createPost = async (content: string): Promise<CreatePostResponse> =
             throw new Error(`HTTP error! status: ${response.status}`);
         }
         
-        return await response.json();
+        const json = await response.json();
+        handlePostApiCode(json);
+        return json;
     } catch (error) {
         console.error('Failed to create post:', error);
         throw error;
@@ -286,6 +308,7 @@ export const postComment = async (commentData: PostCommentRequest): Promise<Post
     }
 
     const json = await response.json();
+    handlePostApiCode(json);
     if (json.code === 1001 && json.data?.id !== undefined) {
       return { id: Number(json.data.id) };
     }
@@ -320,6 +343,7 @@ export const reportPost = async (reportData: { id: number; title: string; conten
       throw new Error(`HTTP error! status: ${response.status}`);
     }
     const json = await response.json();
+    handlePostApiCode(json);
     if (json.code === 1001 && json.data?.id !== undefined) {
       return { id: Number(json.data.id) };
     }
@@ -346,6 +370,7 @@ export const uploadImage = async (file: File): Promise<string> => {
       throw new Error(`HTTP error! status: ${response.status}`);
     }
     const json = await response.json();
+    handlePostApiCode(json);
     if (json.code === 1001 && typeof json.data === 'string') {
       return json.data;
     }
diff --git a/front/src/layouts/MainLayout.tsx b/front/src/layouts/MainLayout.tsx
index 5dd7aa8..94ac58e 100644
--- a/front/src/layouts/MainLayout.tsx
+++ b/front/src/layouts/MainLayout.tsx
@@ -52,7 +52,7 @@ const useStyles = makeStyles({
   }
 });
 
-const LayoutContent = ({ toasterId, imageViewer }: { toasterId: string; imageViewer?: ReactNode }) => {
+const LayoutContent = ({ toasterId, overlays }: { toasterId: string; overlays?: ReactNode }) => {
   const styles = useStyles();
   const { isDarkMode } = useLayout();
 
@@ -71,17 +71,17 @@ const LayoutContent = ({ toasterId, imageViewer }: { toasterId: string; imageVie
         </div>
         <Footer />
         <Toaster toasterId={toasterId} position="top-end" />
-        {imageViewer}
+        {overlays}
       </div>
     </FluentProvider>
   );
 };
 
-export const MainLayout = ({ imageViewer }: { imageViewer?: ReactNode }) => {
+export const MainLayout = ({ overlays }: { overlays?: ReactNode }) => {
   const toasterId = useId('toaster');
   return (
     <LayoutProvider toasterId={toasterId}>
-      <LayoutContent toasterId={toasterId} imageViewer={imageViewer} />
+      <LayoutContent toasterId={toasterId} overlays={overlays} />
     </LayoutProvider>
   );
 };