diff --git a/components/PageHeader.tsx b/components/PageHeader.tsx
index f708a9c..13481a1 100644
--- a/components/PageHeader.tsx
+++ b/components/PageHeader.tsx
@@ -1,4 +1,4 @@
-import { alpha, Box, Stack, SxProps, Theme, Typography } from '@mui/material';
+import { alpha, Box, Stack, SxProps, Theme, Typography, useTheme } from '@mui/material';
 import { ReactNode } from 'react';
 
 /**
@@ -7,7 +7,7 @@ import { ReactNode } from 'react';
 export interface PageHeaderProps {
   /** 要显示的图标组件 */
   icon: ReactNode;
-  /** 图标的颜色，默认为 '#1976d2'（蓝色） */
+  /** 图标的颜色，默认使用主题 primary.main 色 */
   iconColor?: string;
   /** 主标题文本 */
   title: string;
@@ -53,7 +53,7 @@ export interface PageHeaderProps {
  */
 export default function PageHeader({
   icon,
-  iconColor = '#1976d2',
+  iconColor,
   title,
   subtitle,
   badge,
@@ -62,6 +62,9 @@ export default function PageHeader({
   subtitleSx,
   sx,
 }: PageHeaderProps) {
+  const theme = useTheme();
+  const resolvedIconColor = iconColor ?? theme.palette.primary.main;
+
   return (
     <Stack direction="row" spacing={1.5} alignItems="center" sx={{ mb: 2.5, ...sx }}>
       {/* 图标容器 */}
@@ -69,8 +72,8 @@ export default function PageHeader({
         sx={{
           p: 1,
           borderRadius: 2.5,
-          bgcolor: alpha(iconColor, 0.1),
-          color: iconColor,
+          bgcolor: alpha(resolvedIconColor, 0.1),
+          color: resolvedIconColor,
           display: 'flex',
           ...iconSx,
         }}
diff --git a/components/__tests__/PageHeader.test.tsx b/components/__tests__/PageHeader.test.tsx
index a601f24..e567199 100644
--- a/components/__tests__/PageHeader.test.tsx
+++ b/components/__tests__/PageHeader.test.tsx
@@ -2,8 +2,15 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import AccessTimeIcon from '@mui/icons-material/AccessTime';
 import CloseIcon from '@mui/icons-material/Close';
 import { render, screen } from '@testing-library/react';
+import { ThemeProvider, createTheme } from '@mui/material/styles';
 import PageHeader, { type PageHeaderProps } from '@/components/PageHeader';
 
+const theme = createTheme();
+
+function renderWithTheme(ui: React.ReactElement) {
+  return render(<ThemeProvider theme={theme}>{ui}</ThemeProvider>);
+}
+
 describe('PageHeader 组件系统', () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -22,32 +29,37 @@ describe('PageHeader 组件系统', () => {
 
   describe('PageHeader UI 渲染', () => {
     it('应渲染页面标题栏&副标题', () => {
-      render(<PageHeader {...defaultProps} />);
+      renderWithTheme(<PageHeader {...defaultProps} />);
       expect(screen.getByText('时间戳转换')).toBeInTheDocument();
       expect(screen.getByText('Unix 毫秒数转换与格式化')).toBeInTheDocument();
     });
 
     it('应渲染图标', () => {
-      render(<PageHeader {...defaultProps} />);
+      renderWithTheme(<PageHeader {...defaultProps} />);
       expect(screen.getByTestId('AccessTimeIcon')).toBeInTheDocument();
     });
 
     it('应渲染自定义图标&图标颜色', () => {
-      render(<PageHeader {...defaultProps} icon={<CloseIcon />} iconColor="#FF0000" />);
+      renderWithTheme(<PageHeader {...defaultProps} icon={<CloseIcon />} iconColor="#FF0000" />);
       expect(screen.getByTestId('CloseIcon')).toBeInTheDocument();
       expect(screen.getByTestId('CloseIcon')).toHaveStyle('color: #FF0000;');
     });
 
+    it('应默认使用主题 primary 色', () => {
+      renderWithTheme(<PageHeader {...defaultProps} icon={<CloseIcon />} />);
+      expect(screen.getByTestId('CloseIcon')).toHaveStyle(`color: ${theme.palette.primary.main};`);
+    });
+
     it('应渲染 badge 组件', () => {
       const badge = <span data-testid="test-badge">New</span>;
-      render(<PageHeader {...defaultProps} badge={badge} />);
+      renderWithTheme(<PageHeader {...defaultProps} badge={badge} />);
       expect(screen.getByTestId('test-badge')).toBeInTheDocument();
       expect(screen.getByText('New')).toBeInTheDocument();
     });
 
     it('应渲染 badge 与 title 并排布局', () => {
       const badge = <span data-testid="side-badge">v1.0</span>;
-      render(<PageHeader {...defaultProps} badge={badge} />);
+      renderWithTheme(<PageHeader {...defaultProps} badge={badge} />);
       const title = screen.getByText('时间戳转换');
       const badgeEl = screen.getByTestId('side-badge');
       expect(title).toBeInTheDocument();
@@ -57,13 +69,15 @@ describe('PageHeader 组件系统', () => {
 
   describe('PageHeader 条件渲染', () => {
     it('subtitle 为 undefined 时不应渲染副标题', () => {
-      const { container } = render(<PageHeader icon={<AccessTimeIcon />} title="仅标题" />);
+      const { container } = renderWithTheme(
+        <PageHeader icon={<AccessTimeIcon />} title="仅标题" />,
+      );
       const captionElements = container.querySelectorAll('p');
       expect(captionElements.length).toBe(0);
     });
 
     it('subtitle 为空字符串时不应渲染副标题', () => {
-      const { container } = render(
+      const { container } = renderWithTheme(
         <PageHeader icon={<AccessTimeIcon />} title="标题" subtitle="" />,
       );
       const captionElements = container.querySelectorAll('p');
@@ -71,14 +85,14 @@ describe('PageHeader 组件系统', () => {
     });
 
     it('badge 为 undefined 时不应渲染 badge 区域', () => {
-      render(<PageHeader {...defaultProps} />);
+      renderWithTheme(<PageHeader {...defaultProps} />);
       expect(screen.queryByText('v1.0')).not.toBeInTheDocument();
     });
   });
 
   describe('PageHeader 样式扩展', () => {
     it('iconSx 应作为属性传递给图标容器', () => {
-      const { container } = render(
+      const { container } = renderWithTheme(
         <PageHeader {...defaultProps} iconSx={{ border: '2px solid red' }} />,
       );
       const iconContainer = container.querySelector('div');
@@ -86,19 +100,19 @@ describe('PageHeader 组件系统', () => {
     });
 
     it('titleSx 应作为属性传递给标题', () => {
-      render(<PageHeader {...defaultProps} titleSx={{ fontWeight: 'bold' }} />);
+      renderWithTheme(<PageHeader {...defaultProps} titleSx={{ fontWeight: 'bold' }} />);
       const titleEl = screen.getByText('时间戳转换');
       expect(titleEl).toBeInTheDocument();
     });
 
     it('subtitleSx 应作为属性传递给副标题', () => {
-      render(<PageHeader {...defaultProps} subtitleSx={{ color: 'red' }} />);
+      renderWithTheme(<PageHeader {...defaultProps} subtitleSx={{ color: 'red' }} />);
       const subtitleEl = screen.getByText('Unix 毫秒数转换与格式化');
       expect(subtitleEl).toBeInTheDocument();
     });
 
     it('sx 应作为属性传递给外层容器', () => {
-      const { container } = render(<PageHeader {...defaultProps} sx={{ mt: 3 }} />);
+      const { container } = renderWithTheme(<PageHeader {...defaultProps} sx={{ mt: 3 }} />);
       const outerElement = container.firstChild;
       expect(outerElement).toBeTruthy();
     });