diff --git a/Merge/front/src/api/posts_trm.js b/Merge/front/src/api/posts_trm.js
index 8f7e877..2c0fc14 100644
--- a/Merge/front/src/api/posts_trm.js
+++ b/Merge/front/src/api/posts_trm.js
@@ -218,7 +218,11 @@
  * @returns Promise<[ {id, gpu_id, gpu_usage, gpu_memory_usage, timestamp}, … ]>
  */
 export async function fetchGpuUsage(limit = 100) {
-  const token = localStorage.getItem('token')
+  const token = getAuthToken()
+  if (!token || token === 'null') {
+    throw new Error('Token not found or invalid. Please login again.')
+  }
+  
   const res = await fetch(`http://10.126.59.25:8082/gpu-usage?limit=${limit}`, {
     method: 'GET',
     headers: { 
diff --git a/Merge/front/src/components/PerformanceLogs.js b/Merge/front/src/components/PerformanceLogs.js
index 67518de..f0f3d9f 100644
--- a/Merge/front/src/components/PerformanceLogs.js
+++ b/Merge/front/src/components/PerformanceLogs.js
@@ -18,6 +18,12 @@
     const fetchSystemData = fetchSysCost(userId)
       .then(result => {
         // 检查是否是权限错误
+        if (typeof result === 'string' && result.startsWith('<!DOCTYPE')) {
+          // 返回的是 HTML，说明未登录或接口错误
+          setUnauthorized(true);
+          setData([]);
+          return;
+        }
         if (result && result.status === 'error' && result.message === 'Unauthorized') {
           setUnauthorized(true);
           setData([]);
@@ -57,6 +63,11 @@
     // 获取GPU数据
     const fetchGpuData = fetchGpuUsage(100)
       .then(result => {
+        if (typeof result === 'string' && result.startsWith('<!DOCTYPE')) {
+          // 返回的是 HTML，说明未登录或接口错误
+          setGpuData([]);
+          return;
+        }
         console.log('GPU data:', result);
         const processedData = processGpuData(result);
         setGpuData(processedData);
@@ -180,7 +191,7 @@
             />
             <YAxis domain={[0, 100]} label={{ value: '使用率 (%)', angle: -90, position: 'insideLeft' }} />
             <Tooltip 
-              formatter={(val, name) => [`${val?.toFixed(2)}%`, name]}
+              formatter={(val, name) => [`${val != null && typeof val === 'number' ? val.toFixed(2) : val}%`, name]}
               labelFormatter={ts => new Date(ts).toLocaleString()}
             />
             <Legend />
@@ -212,7 +223,7 @@
             />
             <YAxis domain={[0, 'auto']} label={{ value: '内存 (MB)', angle: -90, position: 'insideLeft' }} />
             <Tooltip 
-              formatter={(val, name) => [`${val?.toFixed(2)} MB`, name]}
+              formatter={(val, name) => [`${val != null && typeof val === 'number' ? val.toFixed(2) : val} MB`, name]}
               labelFormatter={ts => new Date(ts).toLocaleString()}
             />
             <Legend />