diff --git a/Service/Jobs/DbBackupJob.cs b/Service/Jobs/DbBackupJob.cs
new file mode 100644
index 0000000..4208fc4
--- /dev/null
+++ b/Service/Jobs/DbBackupJob.cs
@@ -0,0 +1,70 @@
+using Microsoft.Extensions.Hosting;
+using Quartz;
+
+namespace Service.Jobs;
+
+/// <summary>
+/// 数据库备份任务
+/// </summary>
+public class DbBackupJob(
+    IHostEnvironment env,
+    ILogger<DbBackupJob> logger) : IJob
+{
+    public Task Execute(IJobExecutionContext context)
+    {
+        try
+        {
+            logger.LogInformation("开始执行数据库备份任务");
+            
+            // 数据库文件路径 (基于 appsettings.json 中的配置: database/EmailBill.db)
+            var dbPath = Path.Combine(env.ContentRootPath, "database", "EmailBill.db");
+            var backupDir = Path.Combine(env.ContentRootPath, "database", "backups");
+
+            if (!File.Exists(dbPath))
+            {
+                logger.LogWarning("数据库文件不存在，跳过备份: {Path}", dbPath);
+                return Task.CompletedTask;
+            }
+
+            if (!Directory.Exists(backupDir))
+            {
+                Directory.CreateDirectory(backupDir);
+            }
+
+            // 创建备份
+            var backupFileName = $"EmailBill_backup_{DateTime.Now:yyyyMMdd}.db";
+            var backupPath = Path.Combine(backupDir, backupFileName);
+
+            File.Copy(dbPath, backupPath, true);
+            logger.LogInformation("数据库备份成功: {Path}", backupPath);
+
+            // 清理旧备份 (保留最近20个)
+            var files = new DirectoryInfo(backupDir).GetFiles("EmailBill_backup_*.db")
+                .OrderByDescending(f => f.LastWriteTime) // 使用 LastWriteTime 排序
+                .ToList();
+
+            if (files.Count > 20)
+            {
+                var filesToDelete = files.Skip(20);
+                foreach (var file in filesToDelete)
+                {
+                    try 
+                    {
+                        file.Delete();
+                        logger.LogInformation("删除过期备份: {Name}", file.Name);
+                    }
+                    catch (Exception ex)
+                    {
+                        logger.LogError(ex, "删除过期备份失败: {Name}", file.Name);
+                    }
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "数据库备份任务执行失败");
+        }
+
+        return Task.CompletedTask;
+    }
+}
diff --git a/WebApi/Expand.cs b/WebApi/Expand.cs
index e74d1ea..52a9270 100644
--- a/WebApi/Expand.cs
+++ b/WebApi/Expand.cs
@@ -44,6 +44,17 @@ public static class Expand
                 .WithIdentity("BudgetArchiveTrigger")
                 .WithCronSchedule("0 0 23 1 * ?") // 每个月1号晚11点执行
                 .WithDescription("每个月1号晚11点执行预算归档"));
+
+            // 配置数据库备份任务 - 每天早上6点执行
+            var dbBackupJobKey = new JobKey("DbBackupJob");
+            q.AddJob<DbBackupJob>(opts => opts
+                .WithIdentity(dbBackupJobKey)
+                .WithDescription("数据库备份任务"));
+            q.AddTrigger(opts => opts
+                .ForJob(dbBackupJobKey)
+                .WithIdentity("DbBackupTrigger")
+                .WithCronSchedule("0 0 6 * * ?") // 每天早上6点执行
+                .WithDescription("每天早上6点执行数据库备份"));
         });
 
         // 添加 Quartz Hosted Service