diff --git a/TESTING.md b/TESTING.md
new file mode 100644
index 0000000..c065e82
--- /dev/null
+++ b/TESTING.md
@@ -0,0 +1,245 @@
+# 测试框架使用指南
+
+## 概述
+
+项目已配置 **pytest** 测试框架,相比你之前的手动测试方法,有以下优势:
+
+### ✅ 改进点
+
+| 旧方法 (Jupyter Notebook) | 新方法 (pytest) |
+|-------------------------|----------------|
+| 手动运行每个测试用例 | 自动发现和运行所有测试 |
+| 手动读取和对比文件 | 自动化断言和差异报告 |
+| 难以定位失败原因 | 清晰的错误堆栈和 diff |
+| 无法批量运行 | 支持参数化和并行测试 |
+| 无覆盖率统计 | 自动生成覆盖率报告 |
+
+## 快速开始
+
+### 1. 运行所有测试
+```bash
+python -m pytest
+```
+
+### 2. 运行特定测试文件
+```bash
+python -m pytest tests/test_playlist_merge.py -v
+```
+
+### 3. 在 VS Code 中运行
+- 按 `Ctrl+Shift+P`
+- 输入 "Run Task"
+- 选择 "运行所有测试" 或其他测试任务
+
+## 测试文件说明
+
+### 已创建的测试文件
+
+```
+tests/
+├── __init__.py              # 包初始化
+├── conftest.py              # pytest fixtures 和配置
+├── test_playlist_merge.py   # 播放列表合并测试
+└── README.md                # 详细测试指南
+```
+
+### 测试用例覆盖
+
+`test_playlist_merge.py` 包含:
+
+1. **基础功能测试** (`TestPlaylistMergeBasics`)
+   - `test_load_paths_removes_comments` - 测试路径加载
+   - `test_save_paths_adds_header` - 测试文件保存
+   - `test_empty_playlist_merge` - 测试空播放列表合并
+
+2. **本地优先测试** (`TestPlaylistMergeLocalPriority`)
+   - 参数化测试 case1-4 的本地优先合并
+   
+3. **远程优先测试** (`TestPlaylistMergeRemotePriority`)
+   - 参数化测试 case1-4 的远程优先合并
+
+4. **冲突检测测试** (`TestConflictDetection`)
+   - 测试冲突识别和解决
+
+## 常用命令
+
+### 基础运行
+```bash
+# 运行所有测试
+pytest
+
+# 详细输出
+pytest -v
+
+# 显示 print 输出
+pytest -s
+
+# 只运行特定测试
+pytest tests/test_playlist_merge.py::TestPlaylistMergeBasics::test_load_paths_removes_comments
+```
+
+### 测试筛选
+```bash
+# 运行特定 case
+pytest -k "case_num-1"
+
+# 运行包含特定关键字的测试
+pytest -k "local_priority"
+
+# 运行标记的测试
+pytest -m unit
+```
+
+### 调试和重试
+```bash
+# 失败时进入调试器
+pytest --pdb
+
+# 只运行上次失败的测试
+pytest --lf
+
+# 先运行失败的测试
+pytest --ff
+
+# 遇到第一个失败就停止
+pytest -x
+```
+
+### 覆盖率报告
+```bash
+# 生成覆盖率报告
+pytest --cov=app --cov-report=html
+
+# 在浏览器中查看
+# 打开 htmlcov/index.html
+
+# 终端中显示覆盖率
+pytest --cov=app --cov-report=term
+```
+
+## 编写新测试
+
+### 1. 创建测试文件
+在 `tests/` 目录下创建 `test_<feature>.py`
+
+### 2. 编写测试类和函数
+```python
+import pytest
+
+class TestMyFeature:
+    """测试我的功能"""
+    
+    def test_basic_case(self):
+        """测试基本用例"""
+        result = my_function()
+        assert result == expected_value
+    
+    @pytest.mark.parametrize("input,expected", [
+        (1, 2),
+        (2, 4),
+        (3, 6),
+    ])
+    def test_multiple_cases(self, input, expected):
+        """参数化测试多个用例"""
+        assert my_function(input) == expected
+```
+
+### 3. 使用 fixtures
+```python
+@pytest.fixture
+def sample_data():
+    """提供测试数据"""
+    return {"key": "value"}
+
+def test_with_fixture(sample_data):
+    assert sample_data["key"] == "value"
+```
+
+## 与旧测试方法的对比
+
+### 旧方法 (test.ipynb)
+```python
+# 手动循环和对比
+for i in range(len(test_playlists[1])):
+    with open(test_playlists[1][i], 'r', encoding='utf-8') as f1, \
+         open(target_playlists[i], 'r', encoding='utf-8') as f2:
+        content1 = f1.read()
+        content2 = f2.read()
+        # 手动处理和对比...
+        if content1 == content2:
+            print(f"Test case {i+1} passed.")
+        else:
+            print(f"Test case {i+1} failed.")
+```
+
+### 新方法 (pytest)
+```python
+@pytest.mark.parametrize("case_num", [1, 2, 3, 4])
+def test_merge_local_priority(case_num, tmp_path):
+    """自动运行所有用例,失败时显示详细 diff"""
+    # 加载输入
+    base_text = load_file(f"case{case_num}.m3u")
+    # ... 执行测试
+    result = merge_playlists(base_text, local_text, remote_text)
+    # 自动断言和差异报告
+    assert_playlists_equal(actual_file, expected_file)
+```
+
+## 持续集成
+
+可以将测试集成到 CI/CD 流程:
+
+```yaml
+# .github/workflows/test.yml (示例)
+name: Tests
+on: [push, pull_request]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+      - name: Run tests
+        run: pytest --cov=app
+```
+
+## 最佳实践
+
+1. **测试命名** - 使用清晰描述性的名称
+2. **独立性** - 每个测试应该独立运行
+3. **快速** - 单元测试应该快速执行
+4. **明确** - 一个测试只测一个功能点
+5. **维护** - 定期更新测试用例
+
+## 故障排除
+
+### pytest 找不到
+```bash
+python -m pip install pytest pytest-cov
+```
+
+### 导入错误
+确保项目根目录在 Python 路径中:
+```python
+import sys
+sys.path.insert(0, str(Path(__file__).parent.parent))
+```
+
+### 测试发现失败
+检查 `pytest.ini` 配置和文件命名是否符合规范。
+
+## 下一步
+
+- [ ] 为其他模块添加测试 (如 `plex_client.py`, `local_playlist.py`)
+- [ ] 添加集成测试
+- [ ] 配置 CI/CD 自动运行测试
+- [ ] 设置测试覆盖率目标 (如 >80%)
+
+## 参考资料
+
+- [pytest 官方文档](https://docs.pytest.org/)
+- [pytest-cov 文档](https://pytest-cov.readthedocs.io/)
+- 项目内测试: `tests/README.md`
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 0000000..2b1bf3f
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,26 @@
+[pytest]
+# Pytest configuration
+
+# Test discovery patterns
+python_files = test_*.py
+python_classes = Test*
+python_functions = test_*
+
+# Test paths
+testpaths = tests
+
+# Output options
+addopts = 
+    -v
+    --tb=short
+    --strict-markers
+    --disable-warnings
+    
+# Markers for categorizing tests
+markers =
+    slow: marks tests as slow (deselect with '-m "not slow"')
+    integration: marks tests as integration tests
+    unit: marks tests as unit tests
+
+# Minimum version
+minversion = 6.0
diff --git a/tests/README.md b/tests/README.md
new file mode 100644
index 0000000..b20066d
--- /dev/null
+++ b/tests/README.md
@@ -0,0 +1,88 @@
+# 测试指南
+
+## 运行测试
+
+### 运行所有测试
+```bash
+pytest
+```
+
+### 运行特定测试文件
+```bash
+pytest tests/test_playlist_merge.py
+```
+
+### 运行特定测试类或函数
+```bash
+pytest tests/test_playlist_merge.py::TestPlaylistMergeLocalPriority
+pytest tests/test_playlist_merge.py::TestPlaylistMergeLocalPriority::test_merge_local_priority
+```
+
+### 运行特定参数化测试用例
+```bash
+# 只运行 case1 的测试
+pytest tests/test_playlist_merge.py -k "case_num-1"
+```
+
+### 查看详细输出
+```bash
+pytest -v  # verbose
+pytest -vv  # more verbose
+pytest -s  # 显示 print 输出
+```
+
+### 查看测试覆盖率
+```bash
+pip install pytest-cov
+pytest --cov=app --cov-report=html
+```
+然后在浏览器中打开 `htmlcov/index.html`
+
+## 测试结构
+
+- `test_playlist_merge.py` - 播放列表合并功能的单元测试
+- `conftest.py` - pytest fixtures 和配置
+- `pytest.ini` - pytest 配置文件
+
+## 编写新测试
+
+1. 在 `tests/` 目录下创建 `test_*.py` 文件
+2. 创建以 `Test` 开头的测试类
+3. 编写以 `test_` 开头的测试函数
+4. 使用 `assert` 进行断言
+5. 使用 `@pytest.mark.parametrize` 进行参数化测试
+
+示例:
+```python
+import pytest
+
+class TestMyFeature:
+    def test_basic_functionality(self):
+        result = my_function(input_data)
+        assert result == expected_output
+    
+    @pytest.mark.parametrize("input,expected", [
+        (1, 2),
+        (2, 4),
+        (3, 6),
+    ])
+    def test_with_multiple_inputs(self, input, expected):
+        assert my_function(input) == expected
+```
+
+## 调试测试
+
+### 在测试失败时进入调试器
+```bash
+pytest --pdb
+```
+
+### 只运行上次失败的测试
+```bash
+pytest --lf
+```
+
+### 先运行失败的测试
+```bash
+pytest --ff
+```
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..73d90cd
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1 @@
+# Test package initialization
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..d53fcc8
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,45 @@
+"""
+Pytest configuration and shared fixtures.
+"""
+
+import os
+import shutil
+from pathlib import Path
+
+import pytest
+
+
+@pytest.fixture(scope="session")
+def project_root():
+    """Return the project root directory."""
+    return Path(__file__).parent.parent
+
+
+@pytest.fixture(scope="session")
+def test_data_dir(project_root):
+    """Return the test data directory."""
+    return project_root / "test_case"
+
+
+@pytest.fixture(scope="session")
+def expected_results_dir(project_root):
+    """Return the expected results directory."""
+    return project_root / "test_res"
+
+
+@pytest.fixture
+def temp_test_dir(tmp_path):
+    """Create a temporary directory for test output."""
+    test_dir = tmp_path / "test_output"
+    test_dir.mkdir(exist_ok=True)
+    yield test_dir
+    # Cleanup after test (optional)
+    # shutil.rmtree(test_dir, ignore_errors=True)
+
+
+@pytest.fixture(autouse=True)
+def reset_test_state():
+    """Reset any global state before each test."""
+    # Add any necessary cleanup here
+    yield
+    # Post-test cleanup
diff --git a/tests/test_playlist_merge.py b/tests/test_playlist_merge.py
new file mode 100644
index 0000000..cdba70e
--- /dev/null
+++ b/tests/test_playlist_merge.py
@@ -0,0 +1,198 @@
+"""
+Unit tests for playlist merge functionality.
+"""
+
+import os
+from pathlib import Path
+
+import pytest
+
+from app.utils.playlist_merge import (
+    merge_playlists,
+    ConflictResolutionStrategy,
+    load_paths,
+    save_paths,
+)
+
+
+# Test data directory
+TEST_CASE_DIR = Path(__file__).parent.parent / "test_case"
+TEST_RES_DIR = Path(__file__).parent.parent / "test_res"
+DOCKERAPP_TEST_DIR = Path(__file__).parent.parent / "dockerapp" / "test_playlists"
+
+
+def normalize_playlist_content(file_path: str | Path) -> list[str]:
+    """
+    Read a playlist file and return normalized content (without comments/blanks).
+    
+    Args:
+        file_path: Path to the playlist file
+        
+    Returns:
+        List of track paths (non-empty, non-comment lines)
+    """
+    with open(file_path, 'r', encoding='utf-8') as f:
+        content = f.read()
+    
+    # Remove blank lines and comments
+    lines = [
+        line.strip() 
+        for line in content.splitlines() 
+        if line.strip() and not line.startswith('#')
+    ]
+    return lines
+
+
+def assert_playlists_equal(actual_file: str | Path, expected_file: str | Path):
+    """
+    Assert that two playlist files have identical content (ignoring comments).
+    
+    Args:
+        actual_file: Path to the generated playlist
+        expected_file: Path to the expected playlist
+        
+    Raises:
+        AssertionError: If playlists differ
+    """
+    actual_content = normalize_playlist_content(actual_file)
+    expected_content = normalize_playlist_content(expected_file)
+    
+    if actual_content != expected_content:
+        # Provide detailed diff on failure
+        import difflib
+        diff = difflib.unified_diff(
+            expected_content,
+            actual_content,
+            fromfile=str(expected_file),
+            tofile=str(actual_file),
+            lineterm=''
+        )
+        diff_text = '\n'.join(diff)
+        pytest.fail(f"Playlist files differ:\n{diff_text}")
+
+
+class TestPlaylistMergeBasics:
+    """Test basic playlist merge operations."""
+    
+    def test_load_paths_removes_comments(self):
+        """Test that load_paths correctly filters comments and blanks."""
+        text = "#EXTM3U\n\n/path/to/track1.mp3\n#Comment\n/path/to/track2.mp3\n"
+        paths = load_paths(text)
+        assert paths == ["/path/to/track1.mp3", "/path/to/track2.mp3"]
+    
+    def test_save_paths_adds_header(self):
+        """Test that save_paths adds proper m3u header."""
+        paths = ["/path/to/track1.mp3", "/path/to/track2.mp3"]
+        text = save_paths(paths)
+        assert text.startswith("#EXTM3U\n")
+        assert "/path/to/track1.mp3" in text
+        assert "/path/to/track2.mp3" in text
+    
+    def test_empty_playlist_merge(self):
+        """Test merging empty playlists."""
+        result = merge_playlists("", "", "", test_folder=str(DOCKERAPP_TEST_DIR / "empty_test"))
+        assert result.merged_paths == []
+        assert result.conflicts == []
+
+
+@pytest.mark.parametrize("case_num", [1, 2, 3, 4])
+class TestPlaylistMergeLocalPriority:
+    """Test playlist merge with local priority strategy."""
+    
+    def test_merge_local_priority(self, case_num, tmp_path):
+        """Test case {case_num} with local priority."""
+        # Load input files
+        base_file = TEST_CASE_DIR / "base" / f"case{case_num}.m3u"
+        local_file = TEST_CASE_DIR / "local_playlist" / f"case{case_num}.m3u"
+        remote_file = TEST_CASE_DIR / "remote_playlist" / f"case{case_num}.m3u"
+        
+        with open(base_file, 'r', encoding='utf-8') as f:
+            base_text = f.read()
+        with open(local_file, 'r', encoding='utf-8') as f:
+            local_text = f.read()
+        with open(remote_file, 'r', encoding='utf-8') as f:
+            remote_text = f.read()
+        
+        # Create test output folder
+        test_folder = str(tmp_path / f"case{case_num}_local")
+        
+        # Perform merge
+        result = merge_playlists(
+            base_text=base_text,
+            local_text=local_text,
+            remote_text=remote_text,
+            strategy=ConflictResolutionStrategy.LOCAL_PRIORITY,
+            test_folder=test_folder
+        )
+        
+        # Compare with expected result
+        expected_file = TEST_RES_DIR / f"case{case_num}_merged_local_primary.m3u"
+        actual_file = Path(test_folder) / "local_result.m3u8"
+        
+        assert_playlists_equal(actual_file, expected_file)
+
+
+@pytest.mark.parametrize("case_num", [1, 2, 3, 4])
+class TestPlaylistMergeRemotePriority:
+    """Test playlist merge with remote priority strategy."""
+    
+    def test_merge_remote_priority(self, case_num, tmp_path):
+        """Test case {case_num} with remote priority."""
+        # Load input files
+        base_file = TEST_CASE_DIR / "base" / f"case{case_num}.m3u"
+        local_file = TEST_CASE_DIR / "local_playlist" / f"case{case_num}.m3u"
+        remote_file = TEST_CASE_DIR / "remote_playlist" / f"case{case_num}.m3u"
+        
+        with open(base_file, 'r', encoding='utf-8') as f:
+            base_text = f.read()
+        with open(local_file, 'r', encoding='utf-8') as f:
+            local_text = f.read()
+        with open(remote_file, 'r', encoding='utf-8') as f:
+            remote_text = f.read()
+        
+        # Create test output folder
+        test_folder = str(tmp_path / f"case{case_num}_remote")
+        
+        # Perform merge
+        result = merge_playlists(
+            base_text=base_text,
+            local_text=local_text,
+            remote_text=remote_text,
+            strategy=ConflictResolutionStrategy.REMOTE_PRIORITY,
+            test_folder=test_folder
+        )
+        
+        # Compare with expected result
+        expected_file = TEST_RES_DIR / f"case{case_num}_merged_remote_primary.m3u"
+        actual_file = Path(test_folder) / "remote_result.m3u8"
+        
+        assert_playlists_equal(actual_file, expected_file)
+
+
+class TestConflictDetection:
+    """Test conflict detection in merges."""
+    
+    def test_conflict_reporting(self, tmp_path):
+        """Test that conflicts are properly reported."""
+        base = "#EXTM3U\n/track1.mp3\n"
+        local = "#EXTM3U\n/track2.mp3\n"  # Changed
+        remote = "#EXTM3U\n/track3.mp3\n"  # Changed differently
+        
+        result = merge_playlists(
+            base_text=base,
+            local_text=local,
+            remote_text=remote,
+            strategy=ConflictResolutionStrategy.LOCAL_PRIORITY,
+            test_folder=str(tmp_path / "conflict_test")
+        )
+        
+        # Should detect conflict
+        assert len(result.conflicts) > 0
+        
+        # Local priority should prefer local version
+        assert "/track2.mp3" in result.merged_paths
+
+
+if __name__ == "__main__":
+    # Allow running tests directly
+    pytest.main([__file__, "-v"])