diff --git a/docs/strutil.md b/docs/strutil.md
index c086bfa..9ff658e 100644
--- a/docs/strutil.md
+++ b/docs/strutil.md
@@ -58,6 +58,7 @@ import (
 -   [SplitAndTrim](#SplitAndTrim)
 -   [HideString](#HideString)
 -   [RemoveWhiteSpace](#RemoveWhiteSpace)
+-   [SubInBetween](#SubInBetween)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -1274,3 +1275,36 @@ func main() {
     // hello world
 }
 ```
+
+### <span id="SubInBetween">SubInBetween</span>
+
+<p>Return substring between the start and end position(excluded) of source string.</p>
+
+<b>Signature:</b>
+
+```go
+func SubInBetween(str string, start string, end string) string
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/strutil"
+)
+
+func main() {
+    str := "abcde"
+
+    result1 := strutil.SubInBetween(str, "", "de")
+    result2 := strutil.SubInBetween(str, "a", "d")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // abc
+    // bc
+}
+```
\ No newline at end of file
diff --git a/docs/strutil_zh-CN.md b/docs/strutil_zh-CN.md
index de90f24..9a1a118 100644
--- a/docs/strutil_zh-CN.md
+++ b/docs/strutil_zh-CN.md
@@ -58,6 +58,7 @@ import (
 -   [SplitAndTrim](#SplitAndTrim)
 -   [HideString](#HideString)
 -   [RemoveWhiteSpace](#RemoveWhiteSpace)
+-   [SubInBetween](#SubInBetween)
 
 
 <div STYLE="page-break-after: always;"></div>
@@ -1307,3 +1308,36 @@ func main() {
     // hello world
 }
 ```
+
+### <span id="SubInBetween">SubInBetween</span>
+
+<p>获取字符串中指定的起始字符串start和终止字符串end直接的子字符串。</p>
+
+<b>函数签名:</b>
+
+```go
+func SubInBetween(str string, start string, end string) string
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/strutil"
+)
+
+func main() {
+    str := "abcde"
+
+    result1 := strutil.SubInBetween(str, "", "de")
+    result2 := strutil.SubInBetween(str, "a", "d")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // abc
+    // bc
+}
+```
diff --git a/strutil/string.go b/strutil/string.go
index 2498345..54f3b8a 100644
--- a/strutil/string.go
+++ b/strutil/string.go
@@ -5,7 +5,6 @@
 package strutil
 
 import (
-	"reflect"
 	"regexp"
 	"strings"
 	"unicode"
@@ -350,10 +349,7 @@ func RemoveNonPrintable(str string) string {
 
 // StringToBytes converts a string to byte slice without a memory allocation.
 func StringToBytes(str string) (b []byte) {
-	sh := *(*reflect.StringHeader)(unsafe.Pointer(&str))
-	bh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
-	bh.Data, bh.Len, bh.Cap = sh.Data, sh.Len, sh.Len
-	return b
+	return *(*[]byte)(unsafe.Pointer(&str))
 }
 
 // BytesToString converts a byte slice to string without a memory allocation.