diff --git a/desktop/src/components/chat/ThinkingBlock.test.tsx b/desktop/src/components/chat/ThinkingBlock.test.tsx
new file mode 100644
index 00000000..a980af67
--- /dev/null
+++ b/desktop/src/components/chat/ThinkingBlock.test.tsx
@@ -0,0 +1,42 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { cleanup, render, screen } from '@testing-library/react'
+import '@testing-library/jest-dom'
+
+import { ThinkingBlock } from './ThinkingBlock'
+import { useSettingsStore } from '../../stores/settingsStore'
+
+describe('ThinkingBlock', () => {
+  beforeEach(() => {
+    useSettingsStore.setState({ locale: 'zh' })
+  })
+
+  afterEach(() => {
+    cleanup()
+    useSettingsStore.setState({ locale: 'zh' })
+  })
+
+  it('shows the in-progress label while thinking is active', () => {
+    render(<ThinkingBlock content="reasoning..." isActive />)
+    expect(screen.getByRole('button')).toHaveTextContent('思考中')
+    expect(screen.getByRole('button')).not.toHaveTextContent('已思考')
+  })
+
+  it('shows the done label once thinking has completed', () => {
+    render(<ThinkingBlock content="reasoning..." isActive={false} />)
+    expect(screen.getByRole('button')).toHaveTextContent('已思考')
+    expect(screen.getByRole('button')).not.toHaveTextContent('思考中')
+  })
+
+  it('defaults to the done label when isActive is omitted', () => {
+    render(<ThinkingBlock content="reasoning..." />)
+    expect(screen.getByRole('button')).toHaveTextContent('已思考')
+  })
+
+  it('localizes both labels in English', () => {
+    useSettingsStore.setState({ locale: 'en' })
+    const { rerender } = render(<ThinkingBlock content="reasoning..." isActive />)
+    expect(screen.getByRole('button')).toHaveTextContent('Thinking')
+    rerender(<ThinkingBlock content="reasoning..." isActive={false} />)
+    expect(screen.getByRole('button')).toHaveTextContent('Thought')
+  })
+})
diff --git a/desktop/src/components/chat/ThinkingBlock.tsx b/desktop/src/components/chat/ThinkingBlock.tsx
index 284f9a3f..542843be 100644
--- a/desktop/src/components/chat/ThinkingBlock.tsx
+++ b/desktop/src/components/chat/ThinkingBlock.tsx
@@ -28,7 +28,7 @@ export function ThinkingBlock({ content, isActive = false }: { content: string;
           {expanded ? '\u25BE' : '\u25B8'}
         </span>
         <span className="shrink-0 font-medium italic">
-          {t('thinking.label')}
+          {isActive ? t('thinking.label') : t('thinking.labelDone')}
           {isActive && <span className="thinking-dots" />}
         </span>
       </button>
diff --git a/desktop/src/i18n/locales/en.ts b/desktop/src/i18n/locales/en.ts
index c5509b54..b7439d6b 100644
--- a/desktop/src/i18n/locales/en.ts
+++ b/desktop/src/i18n/locales/en.ts
@@ -1304,6 +1304,7 @@ export const en = {
 
   // ─── Thinking Block ──────────────────────────────────────
   'thinking.label': 'Thinking',
+  'thinking.labelDone': 'Thought',
 
   // ─── Tool Calls ──────────────────────────────────────
   'tool.errorOutput': 'Error Output',
diff --git a/desktop/src/i18n/locales/zh.ts b/desktop/src/i18n/locales/zh.ts
index 299e831f..cdcfa270 100644
--- a/desktop/src/i18n/locales/zh.ts
+++ b/desktop/src/i18n/locales/zh.ts
@@ -1306,6 +1306,7 @@ export const zh: Record<TranslationKey, string> = {
 
   // ─── Thinking Block ──────────────────────────────────────
   'thinking.label': '思考中',
+  'thinking.labelDone': '已思考',
 
   // ─── Tool Calls ──────────────────────────────────────
   'tool.errorOutput': '错误输出',