diff --git a/src/test/java/com/example/g8backend/service/PostServiceTest.java b/src/test/java/com/example/g8backend/service/PostServiceTest.java
new file mode 100644
index 0000000..6f54177
--- /dev/null
+++ b/src/test/java/com/example/g8backend/service/PostServiceTest.java
@@ -0,0 +1,152 @@
+package com.example.g8backend.service;
+
+import com.example.g8backend.entity.Post;
+import com.example.g8backend.mapper.PostMapper;
+import com.example.g8backend.service.impl.PostServiceImpl;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+import java.sql.Timestamp;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(SpringExtension.class)
+@DisplayName("帖子服务测试")
+class PostServiceTest {
+
+    @Mock
+    private PostMapper postMapper;
+
+    private PostServiceImpl postService;
+
+    private Post testPost;
+
+    @BeforeEach
+    void setUp() {
+        MockitoAnnotations.openMocks(this);
+        postService = new PostServiceImpl(postMapper);
+        testPost = createTestPost();
+    }
+
+    private Post createTestPost() {
+        Post post = new Post();
+        post.setPostId(1L);
+        post.setUserId(1L);
+        post.setPostTitle("测试标题");
+        post.setPostContent("测试内容");
+        post.setCreatedAt(new Timestamp(System.currentTimeMillis()));
+        return post;
+    }
+
+    @Test
+    @DisplayName("创建帖子-成功")
+    void save_ShouldSucceed() {
+        // Arrange
+        when(postMapper.insert(any(Post.class))).thenReturn(1);
+
+        // Act
+        boolean result = postService.save(testPost);
+
+        // Assert
+        assertTrue(result);
+        verify(postMapper).insert(testPost);
+    }
+
+    @Test
+    @DisplayName("获取帖子-通过ID存在")
+    void getById_WhenExists_ShouldReturnPost() {
+        // Arrange
+        when(postMapper.selectById(1L)).thenReturn(testPost);
+
+        // Act
+        Post result = postService.getById(1L);
+
+        // Assert
+        assertNotNull(result);
+        assertEquals(testPost.getPostId(), result.getPostId());
+        verify(postMapper).selectById(1L);
+    }
+
+    @Test
+    @DisplayName("获取帖子-通过ID不存在")
+    void getById_WhenNotExists_ShouldReturnNull() {
+        // Arrange
+        when(postMapper.selectById(999L)).thenReturn(null);
+
+        // Act
+        Post result = postService.getById(999L);
+
+        // Assert
+        assertNull(result);
+        verify(postMapper).selectById(999L);
+    }
+
+    @Test
+    @DisplayName("更新帖子-成功")
+    void updateById_ShouldSucceed() {
+        // Arrange
+        when(postMapper.updateById(any(Post.class))).thenReturn(1);
+
+        // Act
+        boolean result = postService.updateById(testPost);
+
+        // Assert
+        assertTrue(result);
+        verify(postMapper).updateById(testPost);
+    }
+
+    @Test
+    @DisplayName("删除帖子-成功")
+    void removeById_ShouldSucceed() {
+        // Arrange
+        when(postMapper.deleteById(1L)).thenReturn(1);
+
+        // Act
+        boolean result = postService.removeById(1L);
+
+        // Assert
+        assertTrue(result);
+        verify(postMapper).deleteById(1L);
+    }
+
+    @Test
+    @DisplayName("获取用户帖子列表")
+    void getPostsByUserId_ShouldReturnPosts() {
+        // Arrange
+        List<Post> expectedPosts = Arrays.asList(testPost);
+        when(postMapper.getPostsByUserId(1L)).thenReturn(expectedPosts);
+
+        // Act
+        List<Post> result = postService.getPostsByUserId(1L);
+
+        // Assert
+        assertNotNull(result);
+        assertFalse(result.isEmpty());
+        assertEquals(testPost.getPostId(), result.get(0).getPostId());
+        verify(postMapper).getPostsByUserId(1L);
+    }
+
+    @Test
+    @DisplayName("获取用户帖子-空列表")
+    void getPostsByUserId_WhenNoPosts_ShouldReturnEmptyList() {
+        // Arrange
+        when(postMapper.getPostsByUserId(999L)).thenReturn(Arrays.asList());
+
+        // Act
+        List<Post> result = postService.getPostsByUserId(999L);
+
+        // Assert
+        assertNotNull(result);
+        assertTrue(result.isEmpty());
+        verify(postMapper).getPostsByUserId(999L);
+    }
+}
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