diff --git a/web-vue/src/api/request.js b/web-vue/src/api/request.js
index 5170953..e3d55ac 100644
--- a/web-vue/src/api/request.js
+++ b/web-vue/src/api/request.js
@@ -19,6 +19,22 @@ request.interceptors.request.use(
 request.interceptors.response.use(
   response => response.data,
   error => {
+    // 后端不可用（网络错误、无响应），跳转到登录页
+    if (!error.response) {
+      const isLoginPage = window.location.pathname === '/login'
+      if (!isLoginPage) {
+        localStorage.removeItem('token')
+        localStorage.removeItem('username')
+        localStorage.removeItem('userId')
+        localStorage.removeItem('nickname')
+        localStorage.removeItem('avatar')
+        localStorage.removeItem('storageUsed')
+        localStorage.removeItem('storageLimit')
+        window.location.href = '/login'
+      }
+      return Promise.reject(error)
+    }
+
     const status = error.response?.status
     
     // 只有 401/403 才清理 token 并跳转登录页