diff --git a/backend-java/src/main/java/com/nanri/aiimage/modules/similarasin/controller/SimilarAsinController.java b/backend-java/src/main/java/com/nanri/aiimage/modules/similarasin/controller/SimilarAsinController.java
index 824e74db..e6ed6172 100644
--- a/backend-java/src/main/java/com/nanri/aiimage/modules/similarasin/controller/SimilarAsinController.java
+++ b/backend-java/src/main/java/com/nanri/aiimage/modules/similarasin/controller/SimilarAsinController.java
@@ -1,7 +1,6 @@
 package com.nanri.aiimage.modules.similarasin.controller;
 
 import com.nanri.aiimage.common.api.ApiResponse;
-import com.nanri.aiimage.common.util.DownloadHeaderUtil;
 import com.nanri.aiimage.modules.similarasin.model.dto.SimilarAsinFilterConditionAddRequest;
 import com.nanri.aiimage.modules.similarasin.model.dto.SimilarAsinParseRequest;
 import com.nanri.aiimage.modules.similarasin.model.dto.SimilarAsinParsedPayloadDto;
@@ -23,6 +22,7 @@ import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -33,7 +33,6 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.server.ResponseStatusException;
 
-import java.io.InputStream;
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
@@ -181,38 +180,23 @@ public class SimilarAsinController {
 
     @GetMapping("/results/{resultId}/download")
     @Operation(summary = "下载相似 ASIN 检测结果文件")
-    public void downloadResult(
+    public ResponseEntity<Void> downloadResult(
             @Parameter(description = "结果记录 ID", required = true, example = "1001")
             @PathVariable Long resultId,
             @Parameter(description = "当前用户 ID", required = true, example = "1")
-            @RequestParam("user_id") Long userId,
-            jakarta.servlet.http.HttpServletResponse response) {
+            @RequestParam("user_id") Long userId) {
         ResultDownloadInfo download = service.resolveResultDownloadInfo(resultId, userId);
         if (download.url() == null || download.url().isBlank()) {
             throw new ResponseStatusException(HttpStatus.NOT_FOUND, "暂无可下载结果");
         }
-        try {
-            response.setContentType(download.contentType());
-            if (download.size() > 0) {
-                response.setContentLengthLong(download.size());
-            }
-            DownloadHeaderUtil.setAttachment(response, download.filename());
-            long written = 0L;
-            try (InputStream in = URI.create(download.url()).toURL().openStream()) {
-                byte[] buffer = new byte[65536];
-                int read;
-                while ((read = in.read(buffer)) != -1) {
-                    response.getOutputStream().write(buffer, 0, read);
-                    written += read;
-                }
-                response.getOutputStream().flush();
-            }
-            if (download.size() > 0 && written != download.size()) {
-                log.warn("[相似ASIN] 下载文件大小不一致 结果ID={} 预期字节数={} 实际写出字节数={} 文件名={}",
-                        resultId, download.size(), written, download.filename());
-            }
-        } catch (Exception ex) {
-            throw new ResponseStatusException(HttpStatus.INTERNAL_SERVER_ERROR, "下载失败");
-        }
+        // 结果文件常见百 MB 级（货源结果含图片，单文件可达 130MB+）：
+        // 原先在此流式代理整个对象，请求线程会被下载时长占满，并发时拖垮线程池。
+        // 改为 302 重定向到对象存储直链：① 立即释放 Tomcat 线程；
+        // ② 直链支持 Range，客户端断点续传才真正生效（代理只回 200 全量，续传实际失效）。
+        log.info("[相似ASIN] 结果文件下载重定向 结果ID={} 用户ID={} 文件名={} 字节数={}",
+                resultId, userId, download.filename(), download.size());
+        return ResponseEntity.status(HttpStatus.FOUND)
+                .location(URI.create(download.url()))
+                .build();
     }
 }