diff --git a/app/(chat)/api/chat/_lib/detail-replacement.ts b/app/(chat)/api/chat/_lib/detail-replacement.ts
index 958e9f5ae..660407778 100644
--- a/app/(chat)/api/chat/_lib/detail-replacement.ts
+++ b/app/(chat)/api/chat/_lib/detail-replacement.ts
@@ -305,6 +305,10 @@ export type NormalizedAgentModeSourceImage = {
   assetId: string | null;
 };
 
+export function isMarketplaceProductDetailReferenceId(value: unknown) {
+  return /^product-id-(taobao|1688|douyin|jd)-/i.test(String(value || "").trim());
+}
+
 export type ReplacementReferenceDecision = {
   shouldReplace: boolean;
   containsFurnitureProduct: boolean;
@@ -1771,6 +1775,7 @@ export function buildAgentReplacementPrompt(params: {
   basePrompt: string;
   modeType: "detail_replacement" | "sku_replacement";
   replacementStrategy?: AgentDetailReplacementStrategy;
+  marketplaceProductDetailReference?: boolean;
   referenceLabel: string;
   referenceIndex: number;
   totalReferences: number;
@@ -1823,6 +1828,14 @@ export function buildAgentReplacementPrompt(params: {
   imageOrderLines.push(
     `图片${nextImageIndex}：当前参考图底板（唯一版式基准图），必须保留它的文字排版、信息区、分割线、留白、机位和整体结构。`
   );
+  const marketplaceBrandRemovalLines =
+    params.modeType === "detail_replacement" && params.marketplaceProductDetailReference
+      ? [
+          "【市场ID参考图去品牌规则】当前参考图来自外部市场商品详情，原图里可能包含第三方品牌名、Logo、店铺名、商标、水印、角标、平台标识或商家专属视觉符号；这些都属于污染层，最终结果必须去掉。",
+          "去品牌时只清理品牌/Logo/水印本身：保留原来的版式位置、留白、文字层级和信息结构，可把对应区域处理成干净留白、中性图形、无品牌装饰或与当前页面风格一致的空白占位；不要照抄或变体复刻原商标。",
+          "如果参考图标题、标签或画面中出现可识别的外部品牌字样，不要保留该品牌名，不要换成相似字，不要生成伪 Logo；需要文字时只保留非品牌卖点语义或改成无品牌通用描述。",
+        ]
+      : [];
 
   const scenePlanLines = params.scenePlan
     ? [
@@ -1895,6 +1908,7 @@ export function buildAgentReplacementPrompt(params: {
           "【图片顺序规则】",
           ...imageOrderLines,
           ...scenePlanLines,
+          ...marketplaceBrandRemovalLines,
           "你现在做的是‘仅替换产品’，不是重建场景，也不是重新设计整张详情图。",
           "忽略用户补充提示词里的场景风格、氛围、空间改造要求；这一次只服务于产品主体替换。",
           "最后一张参考图是唯一底板，除产品主体/产品展示区外，其余所有内容都必须保持不变。",
@@ -1921,6 +1935,7 @@ export function buildAgentReplacementPrompt(params: {
           "【图片顺序规则】",
           ...imageOrderLines,
           ...scenePlanLines,
+          ...marketplaceBrandRemovalLines,
           "你现在做的是“详情参考图背景/场景图替换”，不是重新设计整张详情图。",
           "【版式锁层规则】把最后一张参考图当成 PSD 模板：文字、标题、编号、卖点标签、按钮、图标、白底/浅色底、留白、分割线、圆角图片框、图片框裁切边界都属于锁定版式层，不允许移动、缩放、重排或重新设计。",
           "如果参考图是“上方文字/标签白底区 + 下方图片/场景圆角框”的结构，必须原样保留标题区高度、文字换行、文字字号、文字左上角位置、标签位置、图片框起始高度、圆角、左右边距和上下留白；禁止把新场景铺到标题白底区背后。",
diff --git a/app/(chat)/api/chat/route.ts b/app/(chat)/api/chat/route.ts
index 68e97de60..278a9eab4 100644
--- a/app/(chat)/api/chat/route.ts
+++ b/app/(chat)/api/chat/route.ts
@@ -279,6 +279,7 @@ import {
 import {
   analyzeReplacementExecutionPlan,
   buildAgentReplacementPrompt,
+  isMarketplaceProductDetailReferenceId,
   normalizeAgentModeDetailReplacementStrategy,
   normalizeAgentModeReferences,
   normalizeAgentModeSourceImages,
@@ -3465,6 +3466,9 @@ export async function POST(request: Request) {
                 basePrompt: baseReplacementPrompt,
                 modeType: "detail_replacement",
                 replacementStrategy: detailReplacementStrategy,
+                marketplaceProductDetailReference:
+                  isMarketplaceProductDetailReferenceId(reference.id) ||
+                  isMarketplaceProductDetailReferenceId(reference.candidateId),
                 referenceLabel: reference.label,
                 referenceIndex,
                 totalReferences: replacementReferences.length,
@@ -4247,6 +4251,10 @@ export async function POST(request: Request) {
                     : "sku_replacement",
                   replacementStrategy:
                     isDetailReplacementPreset ? detailReplacementStrategy : undefined,
+                  marketplaceProductDetailReference:
+                    isDetailReplacementPreset &&
+                    (isMarketplaceProductDetailReferenceId(reference.id) ||
+                      isMarketplaceProductDetailReferenceId(reference.candidateId)),
                   referenceLabel: reference.label,
                   referenceIndex,
                   totalReferences: replacementReferences.length,