diff --git a/pkg/downloader/protocol/http/fetcher.go b/pkg/downloader/protocol/http/fetcher.go
index d9ed596..d3db8d7 100644
--- a/pkg/downloader/protocol/http/fetcher.go
+++ b/pkg/downloader/protocol/http/fetcher.go
@@ -260,7 +260,7 @@ func (f *Fetcher) fetchChunk(index int) (err error) {
 		return err
 	}
 
-	var buf = make([]byte, 8192)
+	var buf = make([]byte, 64*1024) // 64KB
 
 	// 重试10次
 	for i := 0; i < 10; i++ {