diff --git a/app/(admin)/settings/admin-settings-client.tsx b/app/(admin)/settings/admin-settings-client.tsx
index 68730937f..d57856f34 100644
--- a/app/(admin)/settings/admin-settings-client.tsx
+++ b/app/(admin)/settings/admin-settings-client.tsx
@@ -293,6 +293,7 @@ type StorageFailoverConfig = {
 
 type OssImageMigrationConfig = {
   enabled: boolean;
+  preferAliyunForUploads: boolean;
   sourceStorageConfigId: string;
   targetStorageConfigId: string;
   migrateAfterHours: number;
@@ -321,6 +322,7 @@ const defaultStorageFailoverConfig: StorageFailoverConfig = {
 
 const defaultOssImageMigrationConfig: OssImageMigrationConfig = {
   enabled: true,
+  preferAliyunForUploads: true,
   sourceStorageConfigId: "",
   targetStorageConfigId: "",
   migrateAfterHours: 48,
@@ -789,6 +791,8 @@ export function AdminSettingsClient() {
         },
         ossImageMigrationConfig: {
           enabled: (siteSettingsData as any).ossImageMigrationConfig?.enabled !== false,
+          preferAliyunForUploads:
+            (siteSettingsData as any).ossImageMigrationConfig?.preferAliyunForUploads !== false,
           sourceStorageConfigId: String(
             (siteSettingsData as any).ossImageMigrationConfig?.sourceStorageConfigId || ""
           ).trim(),
@@ -7794,6 +7798,30 @@ export function AdminSettingsClient() {
                 />
               </div>
 
+              <div className="flex items-center justify-between rounded-lg border p-4">
+                <div className="space-y-1">
+                  <Label className="text-sm font-medium">默认使用阿里云 OSS 入口桶</Label>
+                  <p className="text-xs text-muted-foreground">
+                    关闭后新上传图片直接走当前默认存储，不再优先进入阿里云 OSS。
+                  </p>
+                  <p className="text-xs text-muted-foreground">
+                    该开关只影响新图上传入口，不影响下方的转存时间、清理时间、单次批量任务设置。
+                  </p>
+                </div>
+                <Switch
+                  checked={siteSettings.ossImageMigrationConfig.preferAliyunForUploads}
+                  onCheckedChange={(checked) =>
+                    setSiteSettings((prev) => ({
+                      ...prev,
+                      ossImageMigrationConfig: {
+                        ...prev.ossImageMigrationConfig,
+                        preferAliyunForUploads: checked,
+                      },
+                    }))
+                  }
+                />
+              </div>
+
               <div className="grid gap-4 md:grid-cols-2">
                 <div className="space-y-2">
                   <Label>OSS 源桶（可选指定）</Label>
@@ -7809,7 +7837,9 @@ export function AdminSettingsClient() {
                       }))
                     }
                   >
-                    <SelectTrigger>
+                    <SelectTrigger
+                      disabled={!siteSettings.ossImageMigrationConfig.preferAliyunForUploads}
+                    >
                       <SelectValue placeholder="自动选择阿里云 OSS（默认优先）" />
                     </SelectTrigger>
                     <SelectContent>
@@ -7829,6 +7859,11 @@ export function AdminSettingsClient() {
                         ))}
                     </SelectContent>
                   </Select>
+                  {!siteSettings.ossImageMigrationConfig.preferAliyunForUploads ? (
+                    <p className="text-xs text-muted-foreground">
+                      已关闭默认走阿里云 OSS，当前源桶选择不会用于新上传图片。
+                    </p>
+                  ) : null}
                 </div>
 
                 <div className="space-y-2">
diff --git a/app/api/site-settings/route.ts b/app/api/site-settings/route.ts
index 9827942e2..639e87c5a 100644
--- a/app/api/site-settings/route.ts
+++ b/app/api/site-settings/route.ts
@@ -659,6 +659,7 @@ const updateSchema = z.object({
   ossImageMigrationConfig: z
     .object({
       enabled: z.boolean().optional(),
+      preferAliyunForUploads: z.boolean().optional(),
       sourceStorageConfigId: z.string().max(128).optional(),
       targetStorageConfigId: z.string().max(128).optional(),
       migrateAfterHours: z.number().min(1).max(720).optional(),
diff --git a/lib/storage/migration-config.ts b/lib/storage/migration-config.ts
index 2aa5da807..caee3398b 100644
--- a/lib/storage/migration-config.ts
+++ b/lib/storage/migration-config.ts
@@ -2,6 +2,7 @@ export const OSS_MIGRATION_CONFIG_KEY = "oss_image_migration_config";
 
 export type OssImageMigrationConfig = {
   enabled: boolean;
+  preferAliyunForUploads: boolean;
   sourceStorageConfigId: string;
   targetStorageConfigId: string;
   migrateAfterHours: number;
@@ -11,6 +12,7 @@ export type OssImageMigrationConfig = {
 
 export const defaultOssImageMigrationConfig: OssImageMigrationConfig = {
   enabled: true,
+  preferAliyunForUploads: true,
   sourceStorageConfigId: "",
   targetStorageConfigId: "",
   migrateAfterHours: 48,
@@ -51,6 +53,7 @@ export function normalizeOssImageMigrationConfig(
 
   return {
     enabled: raw.enabled !== false,
+    preferAliyunForUploads: raw.preferAliyunForUploads !== false,
     sourceStorageConfigId: String(raw.sourceStorageConfigId || "").trim(),
     targetStorageConfigId: String(raw.targetStorageConfigId || "").trim(),
     migrateAfterHours: normalizedMigrateAfterHours,
@@ -58,4 +61,3 @@ export function normalizeOssImageMigrationConfig(
     batchSize: normalizedBatchSize,
   };
 }
-
diff --git a/lib/storage/service.ts b/lib/storage/service.ts
index 51cbd5cfe..fb1a58cfe 100644
--- a/lib/storage/service.ts
+++ b/lib/storage/service.ts
@@ -254,6 +254,10 @@ function normalizeStorageFailoverConfig(value: unknown): {
 async function resolvePreferredUploadStorageConfig(
   migrationConfig: OssImageMigrationConfig
 ): Promise<StorageConfig | undefined> {
+  if (!migrationConfig.enabled || !migrationConfig.preferAliyunForUploads) {
+    return await getDefaultStorageConfig();
+  }
+
   const preferredAliyunConfig = await getPreferredAliyunStorageConfig({
     preferredId: migrationConfig.sourceStorageConfigId || undefined,
   });