diff --git a/ui-html/webview2/settings/ime-settings/src/modules/about-settings.ts b/ui-html/webview2/settings/ime-settings/src/modules/about-settings.ts
index d68ae285..57a9c6c9 100644
--- a/ui-html/webview2/settings/ime-settings/src/modules/about-settings.ts
+++ b/ui-html/webview2/settings/ime-settings/src/modules/about-settings.ts
@@ -1,3 +1,6 @@
+import { updateConfig } from './config-sync';
+import { setupToggleButton } from './shared';
+
 const UPDATE_MANIFEST_URL = 'https://msime.app/update.json';
 const RELEASES_PAGE_URL = 'https://github.com/metasequoiaime/MetasequoiaImeTsf/releases';
 const REQUEST_TIMEOUT_MS = 10000;
@@ -63,6 +66,10 @@ function setDialogOpen(dialog: HTMLDialogElement, open: boolean): void {
 }
 
 export function setupAboutSettings(): void {
+  setupToggleButton('candidateWindowDiagnosticLogToggleBtn', (active) => {
+    updateConfig('general.candidate_window_diagnostic_log', active);
+  });
+
   const checkButton = document.getElementById('about-check-update');
   const versionLabel = document.querySelector('#about-settings .about-version');
   const statusLabel = document.getElementById('about-update-status');
diff --git a/ui-html/webview2/settings/ime-settings/src/modules/config-sync.ts b/ui-html/webview2/settings/ime-settings/src/modules/config-sync.ts
index 0cfd079e..f4775ab0 100644
--- a/ui-html/webview2/settings/ime-settings/src/modules/config-sync.ts
+++ b/ui-html/webview2/settings/ime-settings/src/modules/config-sync.ts
@@ -90,6 +90,12 @@ export function setupConfigSync(): void {
     if (typeof payload.data?.general?.floating_toolbar === 'boolean') {
       applyToggleState('ftbToggleBtn', payload.data.general.floating_toolbar);
     }
+    if (typeof payload.data?.general?.candidate_window_diagnostic_log === 'boolean') {
+      applyToggleState(
+        'candidateWindowDiagnosticLogToggleBtn',
+        payload.data.general.candidate_window_diagnostic_log
+      );
+    }
     if (typeof payload.data?.input?.word_to_character === 'boolean') {
       applyToggleState('wordToCharacterToggleBtn', payload.data.input.word_to_character);
     }
diff --git a/ui-html/webview2/settings/ime-settings/src/partials/about-settings.html b/ui-html/webview2/settings/ime-settings/src/partials/about-settings.html
index 959097d7..b4315db9 100644
--- a/ui-html/webview2/settings/ime-settings/src/partials/about-settings.html
+++ b/ui-html/webview2/settings/ime-settings/src/partials/about-settings.html
@@ -24,6 +24,18 @@
     </button>
   </div>
 
+  <div class="section candidate-window-diagnostic-section">
+    <div class="section-header">
+      <div>
+        <div class="section-title">候选框诊断日志</div>
+        <div class="quick-phrase-description">仅在排查候选框异常时开启。记录窗口、WebView2、焦点会话和通信状态，不记录输入内容或候选文本。日志位于本地应用数据目录的 metasequoiaime\logs。</div>
+      </div>
+      <div class="ftb-toggle-btn" id="candidateWindowDiagnosticLogToggleBtn" role="switch" aria-checked="false" tabindex="0">
+        <div class="ftb-toggle-knob"></div>
+      </div>
+    </div>
+  </div>
+
   <dialog id="about-update-dialog" class="about-update-dialog" aria-labelledby="about-update-dialog-title">
     <div class="about-update-dialog-body">
       <div id="about-update-dialog-title" class="about-update-dialog-title">发现新版本</div>