diff --git a/src/api/purchase/purchasingrequisition.ts b/src/api/purchase/purchasingrequisition.ts
index 406200d..476610d 100644
--- a/src/api/purchase/purchasingrequisition.ts
+++ b/src/api/purchase/purchasingrequisition.ts
@@ -370,6 +370,15 @@ export function downloadFileById(fileId: string) {
 	});
 }
 
+export function previewFileById(fileId: string) {
+	return request({
+		url: '/purchase/purchasingfiles/previewById',
+		method: 'get',
+		params: { fileId },
+		responseType: 'blob'
+	});
+}
+
 /**
  * 批量获取文件下载地址列表
  * @param purchaseId 采购申请ID
diff --git a/src/views/purchase/purchasingrequisition/FileArchiveDialog.vue b/src/views/purchase/purchasingrequisition/FileArchiveDialog.vue
index 6d6e05d..12da83f 100644
--- a/src/views/purchase/purchasingrequisition/FileArchiveDialog.vue
+++ b/src/views/purchase/purchasingrequisition/FileArchiveDialog.vue
@@ -98,10 +98,10 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed } from 'vue'
+import { ref, computed, onUnmounted } from 'vue'
 import { FolderOpened, Download, Document } from '@element-plus/icons-vue'
 import { useMessage } from '/@/hooks/message'
-import { listDownloadUrls, getArchiveDownloadUrl } from '/@/api/purchase/purchasingrequisition'
+import { listDownloadUrls, getArchiveDownloadUrl, downloadFileById, previewFileById } from '/@/api/purchase/purchasingrequisition'
 import other from '/@/utils/other'
 
 interface FileItem {
@@ -117,6 +117,7 @@ const loading = ref(false)
 const downloading = ref(false)
 const previewVisible = ref(false)
 const previewUrl = ref('')
+const previewLoading = ref(false)
 const purchaseId = ref('')
 const purchaseNo = ref('')
 const fileList = ref<FileItem[]>([])
@@ -155,9 +156,9 @@ const isPdfFile = (fileName: string): boolean => {
   return ext === 'pdf'
 }
 
-const handlePreview = (row: FileItem) => {
-  if (!row.downloadUrl) {
-    useMessage().warning('文件预览地址不存在')
+const handlePreview = async (row: FileItem) => {
+  if (!row.id) {
+    useMessage().warning('文件ID不存在')
     return
   }
 
@@ -167,16 +168,41 @@ const handlePreview = (row: FileItem) => {
     return
   }
 
-  // 使用iframe预览PDF（通过后端下载接口获取文件流）
-  previewUrl.value = row.downloadUrl
+  previewLoading.value = true
   previewVisible.value = true
+  previewUrl.value = ''
+
+  try {
+    const res = await previewFileById(row.id)
+    const blob = res as unknown as Blob
+    const url = window.URL.createObjectURL(blob)
+    previewUrl.value = url
+  } catch (err: any) {
+    useMessage().error(err?.msg || '预览失败')
+    previewVisible.value = false
+  } finally {
+    previewLoading.value = false
+  }
 }
 
-const handleDownloadFile = (row: FileItem) => {
-  if (row.downloadUrl) {
-    window.open(row.downloadUrl, '_blank')
-  } else {
-    useMessage().warning('文件下载地址不存在')
+const handleDownloadFile = async (row: FileItem) => {
+  if (!row.id) {
+    useMessage().warning('文件ID不存在')
+    return
+  }
+  try {
+    const res = await downloadFileById(row.id)
+    const blob = res as unknown as Blob
+    const url = window.URL.createObjectURL(blob)
+    const link = document.createElement('a')
+    link.href = url
+    link.download = row.fileTitle || 'download'
+    document.body.appendChild(link)
+    link.click()
+    document.body.removeChild(link)
+    window.URL.revokeObjectURL(url)
+  } catch (err: any) {
+    useMessage().error(err?.msg || '下载失败')
   }
 }
 
@@ -197,6 +223,12 @@ const handleDownloadAll = () => {
   }
 }
 
+onUnmounted(() => {
+  if (previewUrl.value) {
+    window.URL.revokeObjectURL(previewUrl.value)
+  }
+})
+
 defineExpose({
   open
 })
diff --git a/src/views/purchase/purchasingrequisition/docProcess/DocProcessDialog.vue b/src/views/purchase/purchasingrequisition/docProcess/DocProcessDialog.vue
index 52b6269..eb254f7 100644
--- a/src/views/purchase/purchasingrequisition/docProcess/DocProcessDialog.vue
+++ b/src/views/purchase/purchasingrequisition/docProcess/DocProcessDialog.vue
@@ -261,7 +261,7 @@
         <!-- 需求部门/内审部门操作按钮 -->
         <el-button v-if="canSubmitToAsset" type="primary" @click="handleSubmitToAsset">提交至资产管理处</el-button>
         <!-- 通用操作按钮 -->
-        <el-button v-if="canReturn" type="warning" @click="handleReturn">退回修改</el-button>
+        <el-button v-if="canReturn" type="primary" @click="handleReturn">提交招标代理</el-button>
         <el-button v-if="canComplete" type="success" @click="handleComplete">确认流程结束</el-button>
         <el-button @click="handleClose">关闭</el-button>
       </div>