diff --git a/src/util/slice.rs b/src/util/slice.rs
index 573d4e2e54e8ba70290f244bef4e477d58cf405d..6f07e61469ccf2666bd2c2f1d3c94e55aca0c29b 100644
--- a/src/util/slice.rs
+++ b/src/util/slice.rs
@@ -1,10 +1,7 @@
-use std::{ptr, slice};
-use std::alloc::{alloc, Layout};
+use std::mem;
 use std::borrow::Cow;
 use std::cmp::Ordering;
-use std::mem::ManuallyDrop;
 use std::ops::Deref;
-use std::ptr::{copy, NonNull};
 
 pub struct Slice {
     data: Vec<u8>,
@@ -18,10 +15,8 @@ extern {
 impl Default for Slice {
     /// 构造一个空的 Slice
     fn default() -> Self {
-        unsafe {
-            Self {
-                data: Vec::new()
-            }
+        Self {
+            data: Vec::new()
         }
     }
 }
@@ -45,11 +40,9 @@ impl Slice {
         if self.size() == 0 {
             return Slice::default();
         }
-        unsafe {
-            let sub_data = &(*self.data)[n..self.size()];
-            Self {
-                data: Vec::from(sub_data)
-            }
+        let sub_data = &(*self.data)[n..self.size()];
+        Self {
+            data: Vec::from(sub_data)
         }
     }
 
@@ -71,10 +64,11 @@ impl Slice {
 impl<'a> Slice {
     /// 借取 Slice 中的数据, 调用方只拥有读权限
     pub fn borrow_data(&mut self) -> Cow<'a, String> {
-        let str = unsafe {
-            String::from_raw_parts(self.data.as_mut_ptr(), self.size(), self.size())
-        };
-        Cow::Owned(str)
+        unsafe {
+            // String & Vec<u8> has the same layout
+            let s: &String = mem::transmute(&self.data);
+            Cow::Borrowed(s)
+        }
     }
 }
 
@@ -148,9 +142,7 @@ impl Deref for Slice {
 
     /// Slice 解引用到 &[u8]
     fn deref(&self) -> &Self::Target {
-        unsafe {
-            self.data.deref()
-        }
+            &*self.data
     }
 }
 
diff --git a/src/util/slice_test.rs b/src/util/slice_test.rs
index 9bb11d81d5bfc935f81542339c5684fe560ae067..9eabf5957b93857008ac218e34c8ed4b7d0e3637 100644
--- a/src/util/slice_test.rs
+++ b/src/util/slice_test.rs
@@ -1,78 +1,90 @@
-
 mod test {
+    use std::cmp::Ordering;
     use crate::util::slice::Slice;
 
     #[test]
     fn test_from() {
-        let mut a = Slice::from("123");
-        assert_eq!(String::from("123"), String::from(a))
-
+        // from &str
+        let a0 = Slice::from("123");
+        assert_eq!(String::from("123"), String::from(a0));
+        // from String
+        let a1 = Slice::from(String::from("123"));
+        assert_eq!(String::from("123"), String::from(a1));
     }
 
     #[test]
-    fn test_addr() {
-        let a = 123_u32;
-        let slice = a.to_le_bytes();
-        unsafe {
-            let a_addr = &a as *const u32 as usize;
-            let slice_addr = slice.as_ptr() as usize;
-            println!("a_addr: {}, slice_addr: {}", a_addr, slice_addr);
-        }
+    fn test_empty() {
+        let a0 = Slice::default();
+        assert_eq!(true, a0.empty());
+
+        let a1 = Slice::from("123");
+        assert_eq!(false, a1.empty());
     }
 
     #[test]
-    fn test_size() {
-        let mut a: Vec<u8> = Vec::with_capacity(4);
-        // 把 u32 编码到4个byte中, 在内存中结构为 [a0, a1, a2, a3, ....]
-        // 方式1, 用位移来编码
-        let len = 12_u32; // 长度
-        a.push(len as u8);
-        a.push((len >> 8) as u8);
-        a.push((len >> 16) as u8);
-        a.push((len >> 24) as u8);
+    fn test_remove_prefix() {
+        let a0 = Slice::from("123");
+        let a1 = a0.remove_prefix(1);
+        assert_eq!(2, a1.len());
+    }
 
-        // 方式2, 获取到内存地址直接写
-        // unsafe {
-        //     a.as_mut_ptr().cast::<u32>().write(12);
-        //     指针待偏移量可以这样写
-        //     a.as_mut_ptr().cast::<u32>().offset(0).write(12);
-        //     a.set_len(4);
-        // }
+    #[test]
+    fn test_starts_with() {
+        let a0 = Slice::from("12345");
+        let a1 = a0.remove_prefix(2);
+        assert_eq!(String::from("345"), String::from(a1));
+    }
 
+    #[test]
+    fn test_borrow_data() {
+        let mut a0 = Slice::from("123");
+        let borrowed = a0.borrow_data();
+        assert_eq!(3, borrowed.len());
+        let owned = borrowed.to_owned();
+        assert_eq!(3, owned.len());
+    }
 
-        // 取出数据校验, a 这个 vec 指针指向的数据为 [a0, a1, a2, a3, ....],
-        // 读取地址前4个byte到u32中, 比较原始值
-        let value = unsafe {
-            a.as_ptr().cast::<u32>().read()
-        };
-        assert_eq!(12, value);
+    #[test]
+    fn test_partial_eq() {
+        let a0 = Slice::from("123");
+        let a1 = Slice::from("123");
+        let a2 = Slice::from("234");
+        let a3 = Slice::from("012");
+        assert_eq!(true, a0 == a1);
+        assert_eq!(true, a0 < a2);
+        assert_eq!(true, a0 > a3);
+    }
 
-        // let slice: Slice = String::from("123").into();
-        // assert_eq!(3, slice.size());
+    #[test]
+    fn test_partial_ord() {
+        let a0 = Slice::from("123");
+        let a1 = Slice::from("123");
+        let a2 = Slice::from("234");
+        let a3 = Slice::from("012");
+        assert_eq!(Ordering::Equal, a0.partial_cmp(&a1).unwrap());
+        assert_eq!(Ordering::Less, a0.partial_cmp(&a2).unwrap());
+        assert_eq!(Ordering::Greater, a0.partial_cmp(&a3).unwrap());
     }
 
     #[test]
     fn test_memory_leak() {
         // 申请 100G 内存, 查看是否内存泄漏。如果内存泄漏，程序会OOM
         (0..100_000_000).for_each(|_| {
-            unsafe {
-                // 1k
-                let str = "0123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
-                301230123012301230123012301230123";
-                let _: Slice = str.into();
-            }
+            // 1k
+            let str = "0123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123012301230123012301230123012301230123012301230123012\
+            301230123012301230123012301230123";
+            let _: Slice = str.into();
         })
     }
-
 }
\ No newline at end of file