diff --git a/biji-houdaun/src/main/java/com/test/bijihoudaun/controller/MarkdownController.java b/biji-houdaun/src/main/java/com/test/bijihoudaun/controller/MarkdownController.java
index f2ef4e9..3c28d0a 100644
--- a/biji-houdaun/src/main/java/com/test/bijihoudaun/controller/MarkdownController.java
+++ b/biji-houdaun/src/main/java/com/test/bijihoudaun/controller/MarkdownController.java
@@ -10,6 +10,9 @@ import io.swagger.v3.oas.annotations.Parameter;
 import io.swagger.v3.oas.annotations.Parameters;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.core.userdetails.UserDetails;
 import org.springframework.web.bind.annotation.*;
 
 import java.util.Date;
@@ -36,8 +39,15 @@ public class MarkdownController {
     })
     @GetMapping("/{id}")
     public R<String> getMarkdownContent(@PathVariable Long id) {
-        MarkdownFile file = markdownFileService.getMarkdownById(id);
+        // 获取当前认证状态
+        boolean isAuthenticated = isUserAuthenticated();
+        
+        MarkdownFile file = markdownFileService.getMarkdownById(id, isAuthenticated);
         if (ObjectUtil.isNotNull(file)) {
+            // 如果是私密笔记且用户未认证，只返回标题
+            if (file.getIsPrivate() != null && file.getIsPrivate() == 1 && !isAuthenticated) {
+                return R.success(""); // 返回空内容，只显示标题
+            }
             return R.success(file.getContent());
         }
         return R.fail();
@@ -102,4 +112,20 @@ public class MarkdownController {
         List<MarkdownFileVO> files = markdownFileService.getRecentFiles(12);
         return R.success(files);
     }
+
+    /**
+     * 检查用户是否已认证
+     * @return 是否已认证
+     */
+    private boolean isUserAuthenticated() {
+        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
+        if (authentication == null || !authentication.isAuthenticated()) {
+            return false;
+        }
+        Object principal = authentication.getPrincipal();
+        if (principal instanceof UserDetails) {
+            return true;
+        }
+        return false;
+    }
 }
diff --git a/biji-houdaun/src/main/java/com/test/bijihoudaun/entity/MarkdownFile.java b/biji-houdaun/src/main/java/com/test/bijihoudaun/entity/MarkdownFile.java
index 6c6cfd6..2b42149 100644
--- a/biji-houdaun/src/main/java/com/test/bijihoudaun/entity/MarkdownFile.java
+++ b/biji-houdaun/src/main/java/com/test/bijihoudaun/entity/MarkdownFile.java
@@ -45,4 +45,7 @@ public class MarkdownFile implements Serializable {
 
     @Schema(description = "删除人ID", implementation = Long.class)
     private Long deletedBy;
+
+    @Schema(description = "是否私密 0-公开 1-私密", implementation = Integer.class)
+    private Integer isPrivate;
 }
diff --git a/biji-houdaun/src/main/java/com/test/bijihoudaun/service/MarkdownFileService.java b/biji-houdaun/src/main/java/com/test/bijihoudaun/service/MarkdownFileService.java
index 66a8ef0..bfb29f4 100644
--- a/biji-houdaun/src/main/java/com/test/bijihoudaun/service/MarkdownFileService.java
+++ b/biji-houdaun/src/main/java/com/test/bijihoudaun/service/MarkdownFileService.java
@@ -17,9 +17,10 @@ public interface MarkdownFileService extends IService<MarkdownFile> {
     /**
      * 根据ID获取Markdown文件
      * @param id 文件ID
+     * @param isAuthenticated 是否已认证
      * @return Markdown文件对象
      */
-    MarkdownFile getMarkdownById(Long id);
+    MarkdownFile getMarkdownById(Long id, boolean isAuthenticated);
 
     
     /**
diff --git a/biji-houdaun/src/main/java/com/test/bijihoudaun/service/impl/MarkdownFileServiceImpl.java b/biji-houdaun/src/main/java/com/test/bijihoudaun/service/impl/MarkdownFileServiceImpl.java
index 89030e1..648974d 100644
--- a/biji-houdaun/src/main/java/com/test/bijihoudaun/service/impl/MarkdownFileServiceImpl.java
+++ b/biji-houdaun/src/main/java/com/test/bijihoudaun/service/impl/MarkdownFileServiceImpl.java
@@ -59,8 +59,14 @@ public class MarkdownFileServiceImpl
     }
     
     @Override
-    public MarkdownFile getMarkdownById(Long id) {
-        return this.getById(id);
+    public MarkdownFile getMarkdownById(Long id, boolean isAuthenticated) {
+        MarkdownFile file = this.getById(id);
+        if (file != null && !isAuthenticated && file.getIsPrivate() != null && file.getIsPrivate() == 1) {
+            // 对于未认证用户，私密笔记只返回标题，内容置空
+            file.setContent("");
+            return file;
+        }
+        return file;
     }
 
     
diff --git a/sql/data.sql b/sql/data.sql
index 1aed9b8..d4c7086 100644
--- a/sql/data.sql
+++ b/sql/data.sql
@@ -22,9 +22,10 @@ CREATE TABLE IF NOT EXISTS markdown_file (
      content TEXT NOT NULL,
      created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
      updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
-     is_deleted INTEGER DEFAULT 0,
-     deleted_at DATETIME,
-     deleted_by INTEGER
+    is_deleted INTEGER DEFAULT 0,
+    deleted_at DATETIME,
+    deleted_by INTEGER,
+    is_private INTEGER DEFAULT 0  -- 新增字段：0=公开，1=私密
     );
 
 -- 图片表