diff --git a/packages/service/core/dataset/utils.ts b/packages/service/core/dataset/utils.ts
index 47d81e4e4..7c8d98e6e 100644
--- a/packages/service/core/dataset/utils.ts
+++ b/packages/service/core/dataset/utils.ts
@@ -53,10 +53,9 @@ export function replaceS3KeyToPreviewUrl(documentQuoteText: string, expiredTime:
   if (!documentQuoteText || typeof documentQuoteText !== 'string')
     return documentQuoteText as string;
 
-  const prefixPattern = Object.values(S3Sources)
-    .map((pattern) => `${pattern}\\/[^\\s)]+`)
-    .join('|');
-  const regex = new RegExp(String.raw`(!?)\[([^\]]*)\]\((?!https?:\/\/)(${prefixPattern})\)`, 'g');
+  const prefixes = Object.values(S3Sources);
+  const pattern = prefixes.map((p) => `${p}\\/[^)]+`).join('|');
+  const regex = new RegExp(String.raw`(!?)\[([^\]]*)\]\(\s*(?!https?:\/\/)(${pattern})\s*\)`, 'g');
 
   const matches = Array.from(documentQuoteText.matchAll(regex));
   let content = documentQuoteText;
diff --git a/test/cases/service/core/dataset/utils.test.ts b/test/cases/service/core/dataset/utils.test.ts
new file mode 100644
index 000000000..e69a1a54e
--- /dev/null
+++ b/test/cases/service/core/dataset/utils.test.ts
@@ -0,0 +1,433 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { replaceS3KeyToPreviewUrl } from '@fastgpt/service/core/dataset/utils';
+
+vi.mock('@fastgpt/service/common/s3/utils', () => ({
+  jwtSignS3ObjectKey: vi.fn(
+    (objectKey: string) => `https://example.com/api/system/file/mock-jwt-token-${objectKey}`
+  ),
+  isS3ObjectKey: vi.fn((key: string, source: string) => {
+    if (!key) return false;
+    return key.startsWith(`${source}/`);
+  })
+}));
+
+vi.mock('@fastgpt/service/common/s3/type', () => ({
+  S3Sources: {
+    avatar: 'avatar',
+    chat: 'chat',
+    dataset: 'dataset',
+    temp: 'temp',
+    rawText: 'rawText'
+  }
+}));
+
+describe('replaceS3KeyToPreviewUrl', () => {
+  const expiredTime = new Date('2025-12-31');
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe('边界情况处理', () => {
+    it('空字符串应返回空字符串', () => {
+      const result = replaceS3KeyToPreviewUrl('', expiredTime);
+      expect(result).toBe('');
+    });
+
+    it('null 应返回 null', () => {
+      const result = replaceS3KeyToPreviewUrl(null as unknown as string, expiredTime);
+      expect(result).toBe(null);
+    });
+
+    it('undefined 应返回 undefined', () => {
+      const result = replaceS3KeyToPreviewUrl(undefined as unknown as string, expiredTime);
+      expect(result).toBe(undefined);
+    });
+
+    it('非字符串类型应原样返回', () => {
+      const result = replaceS3KeyToPreviewUrl(123 as unknown as string, expiredTime);
+      expect(result).toBe(123);
+    });
+  });
+
+  // 测试不包含 S3 链接的普通文本
+  describe('普通文本处理', () => {
+    it('纯文本不做任何替换', () => {
+      const text = '这是一段普通文本，不包含任何图片链接';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toBe(text);
+    });
+
+    it('普通 HTTP 链接不做替换', () => {
+      const text = '![image](https://example.com/image.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toBe(text);
+    });
+
+    it('普通 markdown 链接不做替换', () => {
+      const text = '[链接文本](https://example.com/page)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toBe(text);
+    });
+  });
+
+  // 测试 dataset 前缀的 S3 链接替换
+  describe('dataset S3 链接替换', () => {
+    it('应替换 dataset 图片链接', () => {
+      const text =
+        '![image.png](dataset/68fee42e1d416bb5ddc85b19/6901c3071ba2bea567e8d8db/aZos7D-214afce5-4d42-4356-9e05-8164d51c59ae.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+      expect(result).toContain('dataset/68fee42e1d416bb5ddc85b19');
+      expect(result).toMatch(/!\[image\.png\]\(https:\/\/example\.com/);
+    });
+
+    it('应替换 dataset 普通链接（非图片）', () => {
+      const text = '[文档](dataset/68fee42e1d416bb5ddc85b19/6901c3071ba2bea567e8d8db/document.pdf)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+      expect(result).toMatch(/\[文档\]\(https:\/\/example\.com/);
+    });
+  });
+
+  // 测试 chat 前缀的 S3 链接替换
+  describe('chat S3 链接替换', () => {
+    it('应替换 chat 图片链接', () => {
+      const text =
+        '![screenshot.png](chat/691ae29d404d0468717dd747/68ad85a7463006c96379a07/jXfXy8yfGAFs9WJpcWRbAhV2/parsed/9a0f4fed-4edf-4613-a8d6-533af5ae51dc.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+      expect(result).toContain('chat/691ae29d404d0468717dd747');
+    });
+  });
+
+  // 测试多个链接替换
+  describe('多个链接替换', () => {
+    it('应正确替换多个 S3 链接', () => {
+      const text = `这是一段包含多个图片的文本：
+![图片1](dataset/team1/collection1/image1.png)
+一些中间文字
+![图片2](chat/app1/user1/chat1/image2.jpg)
+更多文字
+![外部图片](https://external.com/image3.png)`;
+
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+
+      // dataset 和 chat 链接应被替换
+      expect(result).toContain('mock-jwt-token-dataset/team1/collection1/image1.png');
+      expect(result).toContain('mock-jwt-token-chat/app1/user1/chat1/image2.jpg');
+      // 外部链接不应被替换
+      expect(result).toContain('https://external.com/image3.png');
+    });
+  });
+
+  // 测试不支持的 S3 前缀
+  describe('不支持的 S3 前缀', () => {
+    it('avatar 前缀不应被替换（只支持 dataset 和 chat）', () => {
+      const text = '![头像](avatar/team1/user-avatar.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      // avatar 的 isS3ObjectKey 返回 false（因为只检查 dataset 和 chat）
+      expect(result).toBe(text);
+    });
+
+    it('temp 前缀不应被替换', () => {
+      const text = '![临时文件](temp/team1/temp-file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toBe(text);
+    });
+  });
+
+  // 测试特殊字符处理
+  describe('特殊字符处理', () => {
+    // 中文字符
+    it('文件名包含中文应正常处理', () => {
+      const text = '![中文图片名.png](dataset/team1/collection1/中文文件名.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+    });
+
+    it('alt 文本为空应正常处理', () => {
+      const text = '![](dataset/team1/collection1/no-alt.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toMatch(/!\[\]\(https:\/\/example\.com/);
+    });
+
+    // 日韩文字符
+    it('文件名包含日文应正常处理', () => {
+      const text = '![日本語ファイル](dataset/team1/日本語テスト.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/日本語テスト.png');
+    });
+
+    it('文件名包含韩文应正常处理', () => {
+      const text = '![한국어](dataset/team1/한국어파일.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/한국어파일.png');
+    });
+
+    // Emoji 表情符号
+    it('文件名包含 emoji 应正常处理', () => {
+      const text = '![🎉 celebration](dataset/team1/🎉emoji🚀test.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/🎉emoji🚀test.png');
+    });
+
+    it('alt 文本包含多个 emoji 应正常处理', () => {
+      const text = '![🔥💯🎯](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toMatch(/!\[🔥💯🎯\]\(https:\/\/example\.com/);
+    });
+
+    // 特殊符号
+    it('文件名包含下划线和连字符应正常处理', () => {
+      const text = '![image](dataset/team1/my_file-name_v2.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/my_file-name_v2.png');
+    });
+
+    it('文件名包含 @ 符号应正常处理', () => {
+      const text = '![email](dataset/team1/user@example.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/user@example.png');
+    });
+
+    it('文件名包含 # 符号应正常处理', () => {
+      const text = '![hash](dataset/team1/file#1.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/file#1.png');
+    });
+
+    it('文件名包含 $ 符号应正常处理', () => {
+      const text = '![dollar](dataset/team1/price$100.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/price$100.png');
+    });
+
+    it('文件名包含 % 符号应正常处理', () => {
+      const text = '![percent](dataset/team1/50%off.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/50%off.png');
+    });
+
+    it('文件名包含 + 符号应正常处理', () => {
+      const text = '![plus](dataset/team1/a+b.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/a+b.png');
+    });
+
+    it('文件名包含 = 符号应正常处理', () => {
+      const text = '![equals](dataset/team1/x=1.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/x=1.png');
+    });
+
+    // 多个点号
+    it('文件名包含多个点号应正常处理', () => {
+      const text = '![dots](dataset/team1/file.name.v1.2.3.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/file.name.v1.2.3.png');
+    });
+
+    // 空格相关
+    it('alt 文本包含空格应正常处理', () => {
+      const text = '![image with spaces](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toMatch(/!\[image with spaces\]\(https:\/\/example\.com/);
+    });
+
+    it('文件名包含 URL 编码的空格 %20 应正常处理', () => {
+      const text = '![encoded](dataset/team1/file%20name.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/file%20name.png');
+    });
+
+    // 括号类字符
+    it('alt 文本包含转义方括号不匹配正则，不做替换', () => {
+      // 由于 markdown 正则 [^\]]* 不匹配包含 ] 的 alt 文本，这种情况不会被替换
+      const text = '![image \\[1\\]](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      // 预期不做替换
+      expect(result).toBe(text);
+    });
+
+    it('alt 文本包含圆括号应正常处理', () => {
+      const text = '![image (1)](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+    });
+
+    it('文件名包含花括号应正常处理', () => {
+      const text = '![braces](dataset/team1/file{1}.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/file{1}.png');
+    });
+
+    // 引号
+    it('alt 文本包含单引号应正常处理', () => {
+      const text = "![it's a test](dataset/team1/file.png)";
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toMatch(/!\[it's a test\]\(https:\/\/example\.com/);
+    });
+
+    it('alt 文本包含双引号应正常处理', () => {
+      const text = '![say "hello"](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+    });
+
+    // 反斜杠
+    it('alt 文本包含反斜杠应正常处理', () => {
+      const text = '![path\\to\\file](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+    });
+
+    // 特殊 markdown 字符
+    it('alt 文本包含星号应正常处理', () => {
+      const text = '![*important*](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toMatch(/!\[\*important\*\]\(https:\/\/example\.com/);
+    });
+
+    it('alt 文本包含下划线强调应正常处理', () => {
+      const text = '![_emphasis_](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toMatch(/!\[_emphasis_\]\(https:\/\/example\.com/);
+    });
+
+    it('alt 文本包含反引号应正常处理', () => {
+      const text = '![`code`](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toMatch(/!\[`code`\]\(https:\/\/example\.com/);
+    });
+
+    // 数字和字母混合
+    it('文件名是纯 UUID 格式应正常处理', () => {
+      const text = '![uuid](dataset/team1/550e8400-e29b-41d4-a716-446655440000.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain(
+        'mock-jwt-token-dataset/team1/550e8400-e29b-41d4-a716-446655440000.png'
+      );
+    });
+
+    it('文件名是纯数字应正常处理', () => {
+      const text = '![numbers](dataset/team1/123456789.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/123456789.png');
+    });
+
+    // 超长文件名
+    it('超长文件名应正常处理', () => {
+      const longName = 'a'.repeat(200);
+      const text = `![long](dataset/team1/${longName}.png)`;
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain(`mock-jwt-token-dataset/team1/${longName}.png`);
+    });
+
+    // 阿拉伯文和希伯来文（RTL 文字）
+    it('文件名包含阿拉伯文应正常处理', () => {
+      const text = '![عربي](dataset/team1/ملف.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/ملف.png');
+    });
+
+    // 俄文
+    it('文件名包含俄文应正常处理', () => {
+      const text = '![русский](dataset/team1/файл.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/файл.png');
+    });
+
+    // 泰文
+    it('文件名包含泰文应正常处理', () => {
+      const text = '![ไทย](dataset/team1/ไฟล์.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/ไฟล์.png');
+    });
+
+    // 特殊扩展名
+    it('无扩展名的文件应正常处理', () => {
+      const text = '![noext](dataset/team1/README)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/README');
+    });
+
+    it('双扩展名的文件应正常处理', () => {
+      const text = '![tarball](dataset/team1/archive.tar.gz)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/archive.tar.gz');
+    });
+
+    // 管道符和其他 shell 特殊字符
+    it('文件名包含管道符应正常处理', () => {
+      const text = '![pipe](dataset/team1/a|b.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/a|b.png');
+    });
+
+    it('文件名包含波浪号应正常处理', () => {
+      const text = '![tilde](dataset/team1/~user.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/~user.png');
+    });
+
+    it('文件名包含 & 符号应正常处理', () => {
+      const text = '![ampersand](dataset/team1/a&b.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/a&b.png');
+    });
+
+    // 换行符
+    it('alt 文本不包含换行符时应正常处理', () => {
+      const text = '![single line](dataset/team1/file.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+    });
+
+    // 特殊组合
+    it('文件名包含多种特殊字符组合应正常处理', () => {
+      const text = '![complex](dataset/team1/file_v1.2-beta@test#1$100%off.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/file_v1.2-beta@test#1$100%off.png');
+    });
+
+    it('中英文混合 alt 和文件名应正常处理', () => {
+      const text = '![测试image图片](dataset/team1/test测试file文件.png)';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+      expect(result).toContain('mock-jwt-token-dataset/team1/test测试file文件.png');
+    });
+  });
+
+  // 测试链接格式边界情况
+  describe('链接格式边界情况', () => {
+    it('链接中有空格应正常处理', () => {
+      const text = '![image](  dataset/team1/collection1/image.png  )';
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+
+      expect(result).toContain('https://example.com/api/system/file/mock-jwt-token-');
+    });
+
+    it('混合文本和链接应只替换 S3 链接', () => {
+      const text = `# 标题
+
+普通段落文字 ![S3图片](dataset/team1/file.png) 后续文字
+
+[普通链接](https://google.com)
+
+\`\`\`code
+代码块
+\`\`\``;
+
+      const result = replaceS3KeyToPreviewUrl(text, expiredTime);
+
+      expect(result).toContain(
+        'https://example.com/api/system/file/mock-jwt-token-dataset/team1/file.png'
+      );
+      expect(result).toContain('https://google.com');
+      expect(result).toContain('# 标题');
+    });
+  });
+});