diff --git a/pkg/protocol/multipart.go b/pkg/protocol/multipart.go
index 429049111..e926c947a 100644
--- a/pkg/protocol/multipart.go
+++ b/pkg/protocol/multipart.go
@@ -137,11 +137,11 @@ func WriteMultipartFormFile(w *multipart.Writer, fieldName, fileName string, r i
 	// Auto detect actual multipart content type
 	cbuf := make([]byte, 512)
 	size, err := r.Read(cbuf)
-	if err != nil {
+	if err != nil && err != io.EOF {
 		return err
 	}
 
-	partWriter, err := w.CreatePart(CreateMultipartHeader(fieldName, fileName, http.DetectContentType(cbuf)))
+	partWriter, err := w.CreatePart(CreateMultipartHeader(fieldName, fileName, http.DetectContentType(cbuf[:size])))
 	if err != nil {
 		return err
 	}
diff --git a/pkg/protocol/multipart_test.go b/pkg/protocol/multipart_test.go
index be93b8953..86995d28e 100644
--- a/pkg/protocol/multipart_test.go
+++ b/pkg/protocol/multipart_test.go
@@ -208,6 +208,9 @@ func TestWriteMultipartFormFile(t *testing.T) {
 		t.Fatalf("write multipart error: %s", err)
 	}
 	assert.False(t, strings.Contains(bodyBuffer.String(), f3.Name()))
+
+	// test empty file
+	assert.Nil(t, WriteMultipartFormFile(w, "empty_test", "test.data", bytes.NewBuffer(nil)))
 }
 
 func TestMarshalMultipartForm(t *testing.T) {