diff --git a/test_crawler.py b/test_crawler.py
new file mode 100644
index 0000000..36e5a0d
--- /dev/null
+++ b/test_crawler.py
@@ -0,0 +1,103 @@
+import unittest
+import os
+import re
+import requests
+from unittest.mock import patch, Mock
+from crawler import BilibiliDanmakuCrawler, CONFIG
+
+# 模拟测试数据（无中文字节字符串）
+TEST_BV_VALID = "BV1234567890"
+TEST_CID_VALID = "12345678"
+
+# ---------------------- 测试类（严格遵循 unittest 规范） ----------------------
+class TestBilibiliCrawler(unittest.TestCase):
+    def test_bv_extract(self):
+        """测试用例1：有效URL提取BV号"""
+        url = "https://www.bilibili.com/video/BV1234567890/"
+        bv_regex = re.compile(r"BV[0-9A-Za-z]{10,}")
+        self.assertEqual(bv_regex.search(url).group(), TEST_BV_VALID)
+
+    def test_get_cid(self):
+        """测试用例2：有效BV号获取CID"""
+        mock_resp = Mock(status_code=200)
+        mock_resp.json.return_value = {"code": 0, "data": {"cid": TEST_CID_VALID}}
+        with patch("requests.get", return_value=mock_resp):
+            cid_url = f"https://api.bilibili.com/x/web-interface/view?bvid={TEST_BV_VALID}"
+            resp = requests.get(cid_url, headers=BilibiliDanmakuCrawler().headers, timeout=15)
+            self.assertEqual(resp.json()["data"]["cid"], TEST_CID_VALID)
+
+    def test_danmaku_fetch(self):
+        """测试用例3：有效CID爬取弹幕（无中文字节串）"""
+        mock_cid_resp = Mock(status_code=200)
+        mock_cid_resp.json.return_value = {"code": 0, "data": {"cid": TEST_CID_VALID}}
+        # 修复：字节字符串仅含ASCII字符
+        mock_dm_resp = Mock(status_code=200, content=b'<?xml version="1.0"?><root><d>test danmaku</d></root>')
+        with patch("requests.get", side_effect=[mock_cid_resp, mock_dm_resp]):
+            crawler = BilibiliDanmakuCrawler()
+            danmakus = crawler.get_danmakus(TEST_BV_VALID)
+            self.assertIn("test danmaku", danmakus)  # 同步修改断言
+
+    def test_danmaku_save(self):
+        """测试用例4：弹幕保存文件"""
+        crawler = BilibiliDanmakuCrawler()
+        crawler.video_ids = [TEST_BV_VALID]
+        with patch.object(crawler, "get_danmakus", return_value=["test dm1", "test dm2"]):
+            crawler.crawl_all_danmakus()
+            self.assertTrue(os.path.exists(CONFIG["paths"]["raw_danmakus"]))
+
+    def test_noise_filter(self):
+        """测试用例5：噪声弹幕过滤"""
+        crawler = BilibiliDanmakuCrawler()
+        with patch.object(crawler, "get_danmakus", return_value=["666", "valid content", "a"]):
+            crawler.crawl_all_danmakus()
+            with open(CONFIG["paths"]["raw_danmakus"], "r", encoding="utf-8") as f:
+                lines = [l.strip() for l in f if l.strip()]
+                self.assertEqual(len(lines), 1)
+
+    def test_danmaku_dedup(self):
+        """测试用例6：重复弹幕去重"""
+        crawler = BilibiliDanmakuCrawler()
+        with patch.object(crawler, "get_danmakus", return_value=["dup dm", "dup dm", "unique dm"]):
+            crawler.crawl_all_danmakus()
+            with open(CONFIG["paths"]["raw_danmakus"], "r", encoding="utf-8") as f:
+                lines = [l.strip() for l in f if l.strip()]
+                self.assertEqual(len(lines), 2)
+
+    def test_video_id_limit(self):
+        """测试用例7：视频ID数量限制"""
+        crawler = BilibiliDanmakuCrawler()
+        mock_driver = Mock(session_id="test")
+        mock_elem1 = Mock(get_attribute=Mock(return_value=f"https://bilibili.com/video/{TEST_BV_VALID}1/"))
+        mock_elem2 = Mock(get_attribute=Mock(return_value=f"https://bilibili.com/video/{TEST_BV_VALID}2/"))
+        mock_driver.find_elements.return_value = [mock_elem1, mock_elem2, mock_elem1]
+        with patch.object(crawler, "_init_browser", return_value=mock_driver):
+            CONFIG["max_videos"] = 2
+            crawler.get_video_ids()
+            self.assertEqual(len(crawler.video_ids), 2)
+
+    def test_invalid_bv(self):
+        """测试用例8：无效BV号处理"""
+        mock_resp = Mock(status_code=200)
+        mock_resp.json.return_value = {"code": -404, "message": "video not found"}
+        with patch("requests.get", return_value=mock_resp):
+            crawler = BilibiliDanmakuCrawler()
+            danmakus = crawler.get_danmakus("BVinvalid123")
+            self.assertEqual(len(danmakus), 0)
+
+    def test_timeout_handle(self):
+        """测试用例9：网络超时处理"""
+        with patch("requests.get", side_effect=requests.exceptions.Timeout):
+            crawler = BilibiliDanmakuCrawler()
+            danmakus = crawler.get_danmakus(TEST_BV_VALID)
+            self.assertEqual(len(danmakus), 0)
+
+    def test_connection_error(self):
+        """测试用例10：连接错误处理"""
+        with patch("requests.get", side_effect=requests.exceptions.ConnectionError):
+            crawler = BilibiliDanmakuCrawler()
+            danmakus = crawler.get_danmakus(TEST_BV_VALID)
+            self.assertEqual(len(danmakus), 0)
+
+# ---------------------- 必须保留：触发测试执行 ----------------------
+if __name__ == "__main__":
+    unittest.main(verbosity=2)
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