diff --git a/main.go b/main.go
index 77534e3..41b9cb3 100644
--- a/main.go
+++ b/main.go
@@ -265,10 +265,16 @@ func handleIndex(w http.ResponseWriter, r *http.Request) {
         const token = localStorage.getItem('token') || prompt('请输入访问令牌:');
         if(token) localStorage.setItem('token', token);
         const headers = {'Authorization': 'Bearer ' + token};
-
         function loadTasks() {
             fetch('/api/tasks', {headers})
-                .then(r => r.json())
+                .then(r => {
+                    if (!r.ok) {
+                        localStorage.removeItem('token');
+                        alert('认证失败，请刷新页面重新输入');
+                        throw new Error('Unauthorized');
+                    }
+                    return r.json();
+                })
                 .then(tasks => {
                     const tbody = document.querySelector('#taskTable tbody');
                     tbody.innerHTML = tasks.map(t => {