diff --git a/apps/web/src/pages/generate/GeneratePage.tsx b/apps/web/src/pages/generate/GeneratePage.tsx
index 29ed669a9..fa48251da 100644
--- a/apps/web/src/pages/generate/GeneratePage.tsx
+++ b/apps/web/src/pages/generate/GeneratePage.tsx
@@ -107,7 +107,7 @@ const GeneratePage: React.FC = () => {
   useEffect(() => {
     setPreviewTaskId(null)
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [previewAssetIds, selectedTemplate, duration, videoRatio, titleKey, setPreviewTaskId])
+  }, [previewAssetIds, selectedTemplate, duration, videoRatio, titleKey, bgm, setPreviewTaskId])
 
   const previewAssetsEnabled = currentStep >= 4 && previewAssetIds.length > 0
   const {
diff --git a/apps/web/src/pages/generate/hooks/useGenerateVideo.ts b/apps/web/src/pages/generate/hooks/useGenerateVideo.ts
index 569c05793..e8f1d14dc 100755
--- a/apps/web/src/pages/generate/hooks/useGenerateVideo.ts
+++ b/apps/web/src/pages/generate/hooks/useGenerateVideo.ts
@@ -96,8 +96,10 @@ export function useGenerateVideo(props: UseGenerateVideoProps) {
       // ── Step7 确认生成：优先复用预览产物（秒出），fallback 到全量渲染 ──
       let taskId: string | undefined
 
-      // 主路径：如果有预览任务 ID，调用 confirmGeneration 复用预览产物
-      if (props.previewTaskId) {
+      // 主路径：如果有预览任务 ID 且只生成 1 个视频，调用 confirmGeneration 复用预览产物
+      // generateCount > 1 时需要走 createGenerationTask 支持批量生成
+      const isSingleGenerate = !props.generateCount || props.generateCount === 1
+      if (props.previewTaskId && isSingleGenerate) {
         try {
           console.log(
             "[handleGenerate] 尝试 confirmGeneration 复用预览产物, previewTaskId:",
diff --git a/apps/web/src/pages/generate/hooks/useStep6Cover.ts b/apps/web/src/pages/generate/hooks/useStep6Cover.ts
index 4ddffa546..e863559d6 100644
--- a/apps/web/src/pages/generate/hooks/useStep6Cover.ts
+++ b/apps/web/src/pages/generate/hooks/useStep6Cover.ts
@@ -2,7 +2,7 @@
  * Step 6 封面设置 Hook
  * 封装封面设置的交互逻辑，对接后端封面模板 CRUD API
  */
-import { useCallback, useEffect, useState } from "react"
+import { useCallback, useEffect, useRef, useState } from "react"
 import { message } from "antd"
 import type { CoverConfig, CoverTemplate } from "../types/cover"
 import { generateCover } from "@/api/generation"
@@ -40,6 +40,8 @@ export function useStep6Cover({
   onPreviewTaskCreated,
 }: UseStep6CoverProps) {
   const [generating, setGenerating] = useState(false)
+  // 防竞态：记录当前预览生成的参数指纹，任务完成时校验一致性
+  const previewParamsRef = useRef<string>("")
 
   // ── 封面设置弹窗状态 ──
   const [showCoverSettings, setShowCoverSettings] = useState(false)
@@ -154,6 +156,8 @@ export function useStep6Cover({
         console.log("[Step6] 检测到预览缺失，尝试自动创建预览渲染任务...")
         message.info("正在准备预览视频，请稍候...")
         try {
+          // 记录当前参数指纹，用于任务完成时校验一致性（防竞态）
+          previewParamsRef.current = JSON.stringify({ selectedTemplate, assetIds, titleSettings })
           const previewResp = await createPreview({
             template_id: selectedTemplate,
             asset_ids: assetIds,
@@ -174,7 +178,8 @@ export function useStep6Cover({
               : {}),
           })
           // 将预览任务 ID 暴露给父组件，供 Step7 确认生成时复用（confirmGeneration）
-          if (previewResp.task_id) {
+          const currentFingerprint = JSON.stringify({ selectedTemplate, assetIds, titleSettings })
+          if (previewResp.task_id && previewParamsRef.current === currentFingerprint) {
             onPreviewTaskCreated?.(previewResp.task_id)
           }
           // 轮询等待预览渲染完成：递归 setTimeout 避免请求重叠 + 120s 超时兜底