diff --git a/HybirdFrameworkCore/Utils/BitUtls.cs b/HybirdFrameworkCore/Utils/BitUtls.cs
index c02d181..8c4f63a 100644
--- a/HybirdFrameworkCore/Utils/BitUtls.cs
+++ b/HybirdFrameworkCore/Utils/BitUtls.cs
@@ -61,7 +61,6 @@ public static class BitUtls
         {
             length = length / 8;
             var bt = new byte[length];
-            start = start / 8;
 
             for (var i = start; i < start + length; i++) bt[i - start] = bytes[i];
 
@@ -244,17 +243,23 @@ public static class BitUtls
 
     public static ushort Byte2UInt16(byte[] bytes, int startBit, int length)
     {
-        if (length < 9 || length > 16) throw new ArgumentException("length should be less then 17 and greater then 8");
 
         var sub = Sub(bytes, startBit, length);
+        if (sub.Length == 1)
+        {
+            return Convert.ToUInt16(sub[0]);
+        }
         return BitConverter.ToUInt16(sub, 0);
     }
 
     public static short Byte2Int16(byte[] bytes, int startBit, int length)
     {
-        if (length < 9 || length > 16) throw new ArgumentException("length should be less then 17 and greater then 8");
 
         var sub = Sub(bytes, startBit, length);
+        if (sub.Length == 1)
+        {
+            return Convert.ToInt16(sub[0]);
+        }
         return BitConverter.ToInt16(sub, 0);
     }