diff --git a/lib/agents/psd-template-renderer.ts b/lib/agents/psd-template-renderer.ts
index 12be3d623..750a53140 100644
--- a/lib/agents/psd-template-renderer.ts
+++ b/lib/agents/psd-template-renderer.ts
@@ -9,6 +9,7 @@ import {
   isAgentPsdTextLayerSlot,
   resolveAgentPsdTextLayerEffectiveAlign,
   type AgentPsdTemplate,
+  type AgentPsdTemplateImageLayerSlot,
 } from "@/lib/agents/psd-template-config";
 import type { AgentPsdFont } from "@/lib/agents/psd-font-config";
 import { ensurePsdFontAvailableForRender } from "@/lib/agents/psd-font-runtime";
@@ -175,6 +176,22 @@ function getStoredLayerSourceUrl(layer: AgentPsdTemplate["layers"][number]) {
   );
 }
 
+function getDefaultSourceImageLayer(
+  layers: AgentPsdTemplate["layers"]
+) {
+  const editableImageLayers = layers.filter(
+    (layer): layer is AgentPsdTemplateImageLayerSlot =>
+      isAgentPsdTemplateLayerUserEditable(layer) &&
+      isAgentPsdImageLayerSlot(layer)
+  );
+
+  return (
+    editableImageLayers.find((layer) => layer.isDefaultResultSource) ||
+    editableImageLayers[0] ||
+    null
+  );
+}
+
 function resolveTextOverlayFrame(params: {
   layerWidth: number;
   layerHeight: number;
@@ -445,19 +462,16 @@ export async function renderAgentPsdTemplate(params: {
   const hasDedicatedRenderBase =
     Boolean(renderBaseUrl) &&
     renderBaseUrl !== String(template.previewUrl || "").trim();
+  const defaultSourceImageLayerId =
+    getDefaultSourceImageLayer(orderedTemplateLayers)?.id || "";
   const hasHiddenStaticLayer = orderedTemplateLayers.some(
     (layer) =>
       !isAgentPsdTemplateLayerUserEditable(layer) &&
       hiddenLayerIdSet.has(layer.id)
   );
-  const hasMissingVisibleStoredLayerSource = orderedTemplateLayers.some(
-    (layer) =>
-      !hiddenLayerIdSet.has(layer.id) && !getStoredLayerSourceUrl(layer)
-  );
   const shouldUseRenderBaseFallback =
     hasDedicatedRenderBase &&
-    !hasHiddenStaticLayer &&
-    hasMissingVisibleStoredLayerSource;
+    !hasHiddenStaticLayer;
 
   function getLayerPositionOffset(layerId: string) {
     return normalizeTextPositionOffset(layerPositionOffsets[layerId]);
@@ -510,6 +524,9 @@ export async function renderAgentPsdTemplate(params: {
 
       const storedLayerSourceUrl = getStoredLayerSourceUrl(layer);
       if (!isAgentPsdTemplateLayerUserEditable(layer)) {
+        if (shouldUseRenderBaseFallback) {
+          continue;
+        }
         pushAsset(
           storedLayerSourceUrl,
           "PSD 图层素材",
@@ -660,7 +677,12 @@ export async function renderAgentPsdTemplate(params: {
 
   await prefetchRenderAssets();
 
-  if (shouldUseRenderBaseFallback) {
+  let didAppendRenderBase = false;
+  async function appendRenderBaseOverlay() {
+    if (!shouldUseRenderBaseFallback || didAppendRenderBase) {
+      return;
+    }
+    didAppendRenderBase = true;
     const renderBaseBuffer = await readCachedBuffer(renderBaseUrl, "PSD 模板底图");
     await appendBufferOverlay({
       input: renderBaseBuffer,
@@ -671,22 +693,36 @@ export async function renderAgentPsdTemplate(params: {
     });
   }
 
+  if (
+    shouldUseRenderBaseFallback &&
+    (!defaultSourceImageLayerId || hiddenLayerIdSet.has(defaultSourceImageLayerId))
+  ) {
+    await appendRenderBaseOverlay();
+  }
+
   for (const layer of [...orderedTemplateLayers].reverse()) {
     if (hiddenLayerIdSet.has(layer.id)) {
       continue;
     }
 
     if (!isAgentPsdTemplateLayerUserEditable(layer)) {
+      if (shouldUseRenderBaseFallback) {
+        continue;
+      }
       await appendStoredLayer(layer, { optional: shouldUseRenderBaseFallback });
       continue;
     }
 
     if (isAgentPsdImageLayerSlot(layer)) {
+      const isDefaultSourceImageLayer = layer.id === defaultSourceImageLayerId;
       const assignmentUrl = String(imageAssignments[layer.id] || "").trim();
       if (!assignmentUrl) {
         await appendStoredLayer(layer, {
           optional: shouldUseRenderBaseFallback,
         });
+        if (isDefaultSourceImageLayer) {
+          await appendRenderBaseOverlay();
+        }
         continue;
       }
 
@@ -756,6 +792,9 @@ export async function renderAgentPsdTemplate(params: {
           width: slotOverlay.width,
           height: slotOverlay.height,
         });
+        if (isDefaultSourceImageLayer) {
+          await appendRenderBaseOverlay();
+        }
         if (!didAppend) continue;
         continue;
       }
@@ -823,6 +862,9 @@ export async function renderAgentPsdTemplate(params: {
         width: layer.width,
         height: layer.height,
       });
+      if (isDefaultSourceImageLayer) {
+        await appendRenderBaseOverlay();
+      }
       if (!didAppend) continue;
       continue;
     }