diff --git a/Form1.cs b/Form1.cs
index 9b8e80b..82ce4e7 100644
--- a/Form1.cs
+++ b/Form1.cs
@@ -33,6 +33,9 @@ namespace CheckDownload
 
         /// <summary>在线MD5文件名，从DNS查询获取</summary>
         private string _onlineMd5File = "";
+
+        // 类级别变量，用于存储下载的文件数据
+        private Dictionary<string, (byte[] Data, string ExpectedMd5)> _downloadedFiles = new Dictionary<string, (byte[], string)>();
         /// <summary>已完成下载的文件数</summary>
         private int _completedFiles = 0;
 
@@ -345,7 +348,9 @@ namespace CheckDownload
         /// <returns>下载任务</returns>
         private async Task DownloadUpdatedFiles(Dictionary<string, string> differences)
         {
-            // 设置进度条最大值为需要更新的文件数量
+            // 重置下载状态
+            _completedFiles = 0;
+            _downloadedFiles.Clear();
             Update_Pro.Maximum = differences.Count;
             Update_Pro.Value = 0;
 
@@ -361,6 +366,9 @@ namespace CheckDownload
 
             // 等待所有下载任务完成
             await Task.WhenAll(downloadTasks);
+
+            // 所有文件下载完成后统一校验和保存
+            VerifyAndSaveAllFiles();
         }
 
         /// <summary>
@@ -371,56 +379,110 @@ namespace CheckDownload
         /// <returns>下载任务</returns>
         private async Task DownloadFileWithSemaphore(KeyValuePair<string, string> file, SemaphoreSlim semaphore)
         {
-            // 等待信号量，控制并发数量
             await semaphore.WaitAsync();
             try
             {
-                // 下载并验证文件
-                await DownloadAndVerifyFile(file.Key, file.Value);
-                // 更新进度
-                UpdateProgress();
-            }
-            catch (Exception ex)
-            {
-                UpdateStatus($"下载失败: {file.Key} - {ex.Message}");
+                await DownloadToMemory(file.Key, file.Value);
             }
             finally
             {
-                // 释放信号量，允许其他下载任务执行
                 semaphore.Release();
             }
         }
 
         /// <summary>
-        /// 下载并验证文件
+        /// 下载文件到内存并暂存
         /// </summary>
-        /// <param name="relativePath">文件的相对路径</param>
-        /// <param name="expectedMd5">期望的MD5值</param>
-        /// <returns>下载任务</returns>
-        private async Task DownloadAndVerifyFile(string relativePath, string expectedMd5)
+        private async Task DownloadToMemory(string relativePath, string expectedMd5)
         {
-            // 更新状态显示当前下载进度
-            UpdateStatus($"正在下载 ({Update_Pro.Value + 1}/{Update_Pro.Maximum}): {relativePath}");
-
-            // 获取本地路径和临时文件路径
-            string localPath = GetLocalPath(relativePath);
-            string tempPath = $"{localPath}.tmp";
-
-            // 确保目录存在
-            EnsureDirectoryExists(localPath);
-
-            // 下载文件到临时路径
-            using (var client = new WebClient())
+            try
             {
-                await client.DownloadFileTaskAsync(
-                    new Uri($"{BaseDownloadUrl}File/{relativePath}"),
-                    tempPath);
+                // 更新状态显示当前下载进度
+                int current = Interlocked.Increment(ref _completedFiles);
+                UpdateStatus($"正在下载 ({Update_Pro.Value + 1}/{Update_Pro.Maximum}): {expectedMd5}");
+
+                // 下载文件到内存
+                using (var client = new HttpClient())
+                {
+                    var fileUrl = $"{BaseDownloadUrl}File/{expectedMd5}";
+                    var response = await client.GetAsync(fileUrl);
+                    response.EnsureSuccessStatusCode();
+
+                    byte[] fileData = await response.Content.ReadAsByteArrayAsync();
+
+                    // 存储到内存字典
+                    lock (_downloadedFiles)
+                    {
+                        _downloadedFiles[relativePath] = (fileData, expectedMd5);
+                    }
+                }
+
+                // 更新进度
+                UpdateProgress();
+            }
+            catch (Exception ex)
+            {
+                UpdateStatus($"下载失败: {relativePath} - {ex.Message}");
+                throw;
+            }
+        }
+
+        /// <summary>
+        /// 校验并保存所有已下载的文件
+        /// </summary>
+        private void VerifyAndSaveAllFiles()
+        {
+            UpdateStatus("正在校验文件...");
+
+            // 创建失败文件列表
+            var failedFiles = new List<string>();
+
+            foreach (var item in _downloadedFiles)
+            {
+                string relativePath = item.Key;
+                byte[] data = item.Value.Data;
+                string expectedMd5 = item.Value.ExpectedMd5;
+
+                try
+                {
+                    // 计算内存中数据的MD5
+                    string actualMd5;
+                    using (var md5 = MD5.Create())
+                    {
+                        byte[] hashBytes = md5.ComputeHash(data);
+                        actualMd5 = BitConverter.ToString(hashBytes).Replace("-", "").ToLowerInvariant();
+                    }
+
+                    // 校验MD5
+                    if (actualMd5 != expectedMd5.ToLower())
+                    {
+                        throw new Exception($"MD5校验失败 (期望: {expectedMd5}, 实际: {actualMd5})");
+                    }
+
+                    // 获取本地路径并创建目录
+                    string localPath = GetLocalPath(relativePath);
+                    EnsureDirectoryExists(localPath);
+
+                    // 保存文件
+                    File.WriteAllBytes(localPath, data);
+                }
+                catch (Exception ex)
+                {
+                    UpdateStatus($"文件校验失败: {relativePath} - {ex.Message}");
+                    failedFiles.Add(relativePath);
+                }
             }
 
-            // 验证文件MD5
-            VerifyFileMd5(tempPath, expectedMd5, relativePath);
-            // 替换现有文件
-            ReplaceExistingFile(tempPath, localPath);
+            // 清理失败的文件记录
+            foreach (var failedFile in failedFiles)
+            {
+                _downloadedFiles.Remove(failedFile);
+            }
+
+            if (failedFiles.Count > 0)
+            {
+                throw new Exception($"{failedFiles.Count}个文件校验失败");
+            }
         }
 
         /// <summary>