diff --git a/app/dingtalk-entry/route.ts b/app/dingtalk-entry/route.ts
index eab7c47..79fe7eb 100644
--- a/app/dingtalk-entry/route.ts
+++ b/app/dingtalk-entry/route.ts
@@ -4,7 +4,11 @@ import {
   getAuthSessionCookieCandidates,
   resolveSecureAuthCookieFromRequest,
 } from '@/lib/auth-cookie'
-import { DINGTALK_DIRECT_LOGIN_SOURCE, buildDingtalkOAuthUrl } from '@/lib/dingtalk-oauth'
+import {
+  DINGTALK_DIRECT_LOGIN_SOURCE,
+  buildDingtalkOAuthUrl,
+  getDingtalkOAuthClientId,
+} from '@/lib/dingtalk-oauth'
 import {
   getConfiguredDingtalkCorpId,
   normalizeDingtalkCorpId,
@@ -83,18 +87,58 @@ function createH5LoginPage({
         if (status) status.textContent = text;
       }
 
-      function showError(message) {
+      function stringifyError(error) {
+        if (!error) return '';
+        if (typeof error === 'string') return error;
+        if (error.message) return String(error.message);
+        if (error.errorMessage) return String(error.errorMessage);
+        if (error.errMsg) return String(error.errMsg);
+        if (error.errmsg) return String(error.errmsg);
+        try {
+          return JSON.stringify(error);
+        } catch (e) {
+          return String(error);
+        }
+      }
+
+      function appendFallbackLink() {
+        if (!status) return;
+        status.appendChild(document.createElement('br'));
+        status.appendChild(document.createElement('br'));
+        var link = document.createElement('a');
+        link.href = fallbackOAuthUrl;
+        link.textContent = '改用网页授权登录';
+        status.appendChild(link);
+      }
+
+      function showError(message, detail) {
         if (status) {
           status.textContent = message + '。请返回钉钉重新打开通知，或联系管理员检查钉钉免登配置。';
-          status.appendChild(document.createElement('br'));
-          status.appendChild(document.createElement('br'));
-          var link = document.createElement('a');
-          link.href = fallbackOAuthUrl;
-          link.textContent = '改用网页授权登录';
-          status.appendChild(link);
+          if (detail) {
+            status.appendChild(document.createElement('br'));
+            status.appendChild(document.createTextNode('错误详情：' + String(detail).slice(0, 180)));
+          }
+          appendFallbackLink();
         }
       }
 
+      function fallbackToOAuth(message, error) {
+        var detail = stringifyError(error);
+        console.log('DingTalk H5 login fallback:', message, detail || error || '');
+        if (status) {
+          status.textContent = message + '，正在改用网页授权登录...';
+          if (detail) {
+            status.appendChild(document.createElement('br'));
+            status.appendChild(document.createTextNode('错误详情：' + detail.slice(0, 180)));
+          }
+          appendFallbackLink();
+        }
+
+        setTimeout(function () {
+          window.location.replace(fallbackOAuthUrl);
+        }, 900);
+      }
+
       window.__failDingtalkLogin = showError;
 
       function completeProfile(user) {
@@ -136,6 +180,70 @@ function createH5LoginPage({
           });
       }
 
+      function resolveAuthCode(result) {
+        return result && (result.code || result.authCode || result.auth_code);
+      }
+
+      function requestAuthCodeWithFallback(dd, previousError) {
+        if (dd.getAuthCode) {
+          setStatus('正在尝试钉钉新版免登接口...');
+          try {
+            var promiseResult = dd.getAuthCode({ corpId: corpId });
+            if (promiseResult && typeof promiseResult.then === 'function') {
+              promiseResult
+                .then(function (result) {
+                  var code = resolveAuthCode(result);
+                  if (!code) {
+                    fallbackToOAuth('钉钉新版免登接口未返回授权码', result || previousError);
+                    return;
+                  }
+                  submitCode(code);
+                })
+                .catch(function (error) {
+                  fallbackToOAuth('钉钉免登授权失败', error || previousError);
+                });
+              return;
+            }
+
+            var directCode = resolveAuthCode(promiseResult);
+            if (directCode) {
+              submitCode(directCode);
+              return;
+            }
+          } catch (error) {
+            fallbackToOAuth('钉钉免登授权失败', error || previousError);
+            return;
+          }
+        }
+
+        if (dd.requestAuthCode) {
+          setStatus('正在尝试钉钉备用免登接口...');
+          try {
+            dd.requestAuthCode({
+              corpId: corpId,
+              clientId: ${stringifyForInlineScript(getDingtalkOAuthClientId())},
+              onSuccess: function (result) {
+                var code = resolveAuthCode(result);
+                if (!code) {
+                  fallbackToOAuth('钉钉备用免登接口未返回授权码', result || previousError);
+                  return;
+                }
+                submitCode(code);
+              },
+              onFail: function (error) {
+                fallbackToOAuth('钉钉免登授权失败', error || previousError);
+              }
+            });
+            return;
+          } catch (error) {
+            fallbackToOAuth('钉钉免登授权失败', error || previousError);
+            return;
+          }
+        }
+
+        fallbackToOAuth('钉钉免登授权失败', previousError);
+      }
+
       window.__startDingtalkLogin = function () {
         if (started) return;
         started = true;
@@ -143,19 +251,19 @@ function createH5LoginPage({
 
         var dd = window.dd;
         if (!dd || !dd.ready || !dd.runtime || !dd.runtime.permission) {
-          showError('当前页面未检测到钉钉客户端环境');
+          fallbackToOAuth('当前页面未检测到钉钉客户端环境');
           return;
         }
 
         var readyTimer = setTimeout(function () {
-          showError('钉钉免登初始化超时');
+          fallbackToOAuth('钉钉免登初始化超时');
         }, 15000);
 
         if (dd.error) {
           dd.error(function (error) {
             console.log('DingTalk JSAPI error:', error);
             clearTimeout(readyTimer);
-            showError('钉钉免登初始化失败');
+            fallbackToOAuth('钉钉免登初始化失败', error);
           });
         }
 
@@ -173,7 +281,7 @@ function createH5LoginPage({
             },
             onFail: function (error) {
               console.log('requestAuthCode failed:', error);
-              showError('钉钉免登授权失败');
+              requestAuthCodeWithFallback(dd, error);
             }
           });
         });
@@ -187,7 +295,7 @@ function createH5LoginPage({
       ];
       var scriptIndex = 0;
       var loadTimer = setTimeout(function () {
-        if (!started) showError('钉钉免登组件加载超时');
+        if (!started) fallbackToOAuth('钉钉免登组件加载超时');
       }, 15000);
 
       function loadDingtalkScript() {
@@ -206,7 +314,7 @@ function createH5LoginPage({
           }
 
           clearTimeout(loadTimer);
-          showError('钉钉 JSAPI 加载失败');
+          fallbackToOAuth('钉钉 JSAPI 加载失败');
         };
         document.head.appendChild(script);
       }