diff --git a/lib/ai/providers/volcano-vision.ts b/lib/ai/providers/volcano-vision.ts
index 9d89e32ea..f7fc4c781 100644
--- a/lib/ai/providers/volcano-vision.ts
+++ b/lib/ai/providers/volcano-vision.ts
@@ -1,12 +1,73 @@
 import "server-only";
 
 import { uploadFile } from "@/lib/storage/service";
+import { getDefaultStorageConfig } from "@/lib/db/queries";
 
 interface VolcanoVisionConfig {
   apiKey: string;
   baseURL: string;
 }
 
+type VolcanoUrlRewriteConfig = {
+  publicOrigin: string;
+  endpointBase: string;
+  bucket: string;
+};
+
+let cachedRewriteConfig: VolcanoUrlRewriteConfig | null | undefined;
+
+async function getVolcanoUrlRewriteConfig(): Promise<VolcanoUrlRewriteConfig | null> {
+  if (cachedRewriteConfig !== undefined) {
+    return cachedRewriteConfig;
+  }
+
+  try {
+    const storageConfig = await getDefaultStorageConfig();
+    if (
+      !storageConfig ||
+      storageConfig.type !== "s3" ||
+      !storageConfig.endpoint ||
+      !storageConfig.bucket ||
+      !storageConfig.publicUrl
+    ) {
+      cachedRewriteConfig = null;
+      return null;
+    }
+
+    const publicOrigin = new URL(storageConfig.publicUrl).origin;
+    const endpointBase = storageConfig.endpoint.replace(/\/+$/, "");
+
+    cachedRewriteConfig = {
+      publicOrigin,
+      endpointBase,
+      bucket: storageConfig.bucket,
+    };
+    return cachedRewriteConfig;
+  } catch {
+    cachedRewriteConfig = null;
+    return null;
+  }
+}
+
+async function rewriteUploadPublicUrlForVolcano(url: string): Promise<string> {
+  if (!/^https?:\/\//i.test(url)) return url;
+
+  const config = await getVolcanoUrlRewriteConfig();
+  if (!config) return url;
+
+  try {
+    const parsed = new URL(url);
+    if (parsed.origin !== config.publicOrigin) return url;
+    if (!parsed.pathname.startsWith("/uploads/")) return url;
+
+    const rewritten = `${config.endpointBase}/${config.bucket}${parsed.pathname}${parsed.search}`;
+    console.log("[Volcano Vision] Rewrote upload URL for provider fetch:", rewritten);
+    return rewritten;
+  } catch {
+    return url;
+  }
+}
+
 /**
  * 压缩图片生成缩略图（使用 sharp）
  */
@@ -251,11 +312,13 @@ async function convertMessagesToVolcanoFormat(messages: any[]): Promise<{ prompt
       // Base64格式：需要先上传到S3获取URL
       console.log("[Volcano Vision] Found Base64 image, uploading to S3...");
       const uploaded = await uploadImageToS3(imageUrl);
-      processedImages.push(uploaded.original);
+      const rewritten = await rewriteUploadPublicUrlForVolcano(uploaded.original);
+      processedImages.push(rewritten);
     } else {
       // URL格式：直接使用
-      processedImages.push(imageUrl);
-      console.log("[Volcano Vision] Using image URL directly:", imageUrl.substring(0, 80) + "...");
+      const rewritten = await rewriteUploadPublicUrlForVolcano(imageUrl);
+      processedImages.push(rewritten);
+      console.log("[Volcano Vision] Using image URL directly:", rewritten.substring(0, 80) + "...");
     }
   }