diff --git a/server.js b/server.js
index c6cb717..ebcb747 100644
--- a/server.js
+++ b/server.js
@@ -178,10 +178,10 @@ function httpStatusCheck(line, timeoutMs = 8000) {
     }, (res) => {
       res.resume();
       const badGateway = [520, 521, 522, 523, 524].includes(res.statusCode);
-      resolve(!badGateway);
+      resolve({ ok: !badGateway, detail: `HTTP ${res.statusCode}` });
     });
-    req.on('timeout', () => { req.destroy(); resolve(false); });
-    req.on('error', () => resolve(false));
+    req.on('timeout', () => { req.destroy(); resolve({ ok: false, detail: 'HTTP请求超时' }); });
+    req.on('error', (err) => resolve({ ok: false, detail: `HTTP错误：${err.code || err.message}` }));
     req.end();
   });
 }
@@ -189,11 +189,11 @@ function wsHandshakeCheck(line, timeoutMs = 8000) {
   return new Promise((resolve) => {
     let done = false;
     let ws;
-    const finish = (ok) => {
+    const finish = (ok, detail) => {
       if (done) return;
       done = true;
       try { ws && ws.terminate(); } catch (e) {}
-      resolve(ok);
+      resolve({ ok, detail });
     };
     try {
       const port = Number(line.port) || 443;
@@ -203,25 +203,31 @@ function wsHandshakeCheck(line, timeoutMs = 8000) {
         headers: { Host: routeName },
         servername: line.sni || routeName, // TLS SNI
       });
-      ws.on('open', () => finish(true));
-      ws.on('unexpected-response', () => finish(false));
-      ws.on('error', () => finish(false));
+      ws.on('open', () => finish(true, 'WS握手成功'));
+      ws.on('unexpected-response', (req2, res2) => finish(false, `WS握手被拒绝：HTTP ${res2 && res2.statusCode}`));
+      ws.on('error', (err) => finish(false, `WS错误：${err.code || err.message}`));
     } catch (e) {
-      finish(false);
+      finish(false, `WS异常：${e.message}`);
     }
-    setTimeout(() => finish(false), timeoutMs + 500);
+    setTimeout(() => finish(false, 'WS握手超时'), timeoutMs + 500);
   });
 }
 
+// 返回 { ok, detail } —— detail只在vless-cdn时有意义（http/ws两段各自的失败原因），
+// 方便"立即检测"排查究竟是端口/Host/SNI哪一环出的问题，而不是只有一个"异常"看不出所以然。
 async function checkLineConnectivity(line) {
   if (line.protocol === 'vless-cdn') {
-    const [httpOk, wsOk] = await Promise.all([
+    const [httpResult, wsResult] = await Promise.all([
       httpStatusCheck(line),
       wsHandshakeCheck(line),
     ]);
-    return httpOk && wsOk;
+    return {
+      ok: httpResult.ok && wsResult.ok,
+      detail: `HTTP探测: ${httpResult.detail} | WS握手: ${wsResult.detail}`,
+    };
   }
-  return tcpCheck(line.addr, line.port);
+  const tcpOk = await tcpCheck(line.addr, line.port);
+  return { ok: tcpOk, detail: tcpOk ? 'TCP连通' : 'TCP连接失败/超时' };
 }
 
 // 后台定时巡检：每 JMS_CHECK_INTERVAL_MS 跑一轮，只在状态发生变化（正常↔异常）时才发Telegram，
@@ -237,12 +243,12 @@ async function runJmsMonitorCycle() {
 
   for (const line of lines) {
     try {
-      const ok = await checkLineConnectivity(line);
+      const { ok, detail } = await checkLineConnectivity(line);
       const newStatus = ok ? 'normal' : 'abnormal';
       if (line.monitorStatus && line.monitorStatus !== newStatus) {
         const name = line.name || line.addr;
         const msg = newStatus === 'abnormal'
-          ? `⚠️ <b>${name}</b> 检测异常，无法连接\n协议：${line.protocol}\n地址：${line.addr}:${line.port}`
+          ? `⚠️ <b>${name}</b> 检测异常，无法连接\n协议：${line.protocol}\n地址：${line.addr}:${line.port}\n详情：${detail}`
           : `✅ <b>${name}</b> 已恢复正常\n协议：${line.protocol}\n地址：${line.addr}:${line.port}`;
         sendTelegramMessage(msg).catch(() => {}); // Telegram没配置/发送失败都不影响检测本身
       }
@@ -568,16 +574,16 @@ app.post('/api/jms/check-line', requireAuth, jmsCheckLimiter, async (req, res) =
   const line = req.body && req.body.line;
   if (!line || !line.addr) return res.status(400).json({ error: '线路信息不完整' });
   try {
-    const ok = await checkLineConnectivity(line);
+    const { ok, detail } = await checkLineConnectivity(line);
     const newStatus = ok ? 'normal' : 'abnormal';
     if (line.monitorStatus && line.monitorStatus !== newStatus) {
       const name = line.name || line.addr;
       const msg = newStatus === 'abnormal'
-        ? `⚠️ <b>${name}</b> 检测异常，无法连接\n协议：${line.protocol}\n地址：${line.addr}:${line.port}`
+        ? `⚠️ <b>${name}</b> 检测异常，无法连接\n协议：${line.protocol}\n地址：${line.addr}:${line.port}\n详情：${detail}`
         : `✅ <b>${name}</b> 已恢复正常\n协议：${line.protocol}\n地址：${line.addr}:${line.port}`;
       sendTelegramMessage(msg).catch(() => {});
     }
-    res.json({ ok: true, status: newStatus, checkedAt: Date.now() });
+    res.json({ ok: true, status: newStatus, detail, checkedAt: Date.now() });
   } catch (e) {
     res.status(500).json({ error: e.message });
   }