diff --git a/server-rs/crates/api-server/src/tripo3d/artifacts.rs b/server-rs/crates/api-server/src/tripo3d/artifacts.rs
index c65ccb99a..179455594 100644
--- a/server-rs/crates/api-server/src/tripo3d/artifacts.rs
+++ b/server-rs/crates/api-server/src/tripo3d/artifacts.rs
@@ -24,7 +24,7 @@ pub(crate) struct DownloadedArtifact {
 pub(crate) async fn read_artifact(
     mut artifact: TripoDownloadedArtifact,
 ) -> Result<DownloadedArtifact, AppError> {
-    let content_type = artifact.content_type.clone().unwrap_or_default();
+    let content_type = artifact.content_type.take().unwrap_or_default();
     // 按声明长度预分配（封顶到单产物上限，防止 provider 谎报长度撑爆内存）：
     // 几百 MB 的模型逐块 append 会反复搬移，预分配把峰值与拷贝都压下来。
     let claimed_bytes = artifact