diff --git a/src/util/slice.rs b/src/util/slice.rs
index fd12e02484ef6ca5966f41843266d88e29a728db..b767f8d8a03382929589ec2a39754ff816a83142 100644
--- a/src/util/slice.rs
+++ b/src/util/slice.rs
@@ -24,7 +24,7 @@ impl Default for Slice {
 impl Slice {
 
     /// 从 &mut [u8] 转到 Slice, 这里存在内存拷贝开销
-    pub fn from_buf(buf: &mut [u8]) -> Self {
+    pub fn from_buf(buf: &[u8]) -> Self {
         Self {
             data: buf.to_owned()
         }