diff --git a/README.md b/README.md
index eebf54c..b99b350 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,10 @@ This library is now complete, the remaining work is mainly maintenance and bug f
 
 # Change Log
 
+**V1.1.6 2024.2.25**
+
++ Fix the bug of the pkg's length may longer than maximum(without head, tail and pkg length, it's 63 Bytes).
+
 **V1.1.5 2024.2.23**
 
 + Fix the bug of the pack vector may be accessed out of range.
diff --git a/library.properties b/library.properties
index 9a4cd07..06e57ae 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name= DLLN3X ZigBee Mesh Module Library 
-version= 1.1.5
+version= 1.1.6
 author= Dylan Liu <mentalflow@ourdocs.cn>
 maintainer= Dylan Liu <mentalflow@ourdocs.cn>
 sentence= This library allows you to use DLLN3X ZigBee mesh module very easily.
diff --git a/src/DLLN3X.cpp b/src/DLLN3X.cpp
index 2da8033..b05bd64 100644
--- a/src/DLLN3X.cpp
+++ b/src/DLLN3X.cpp
@@ -68,16 +68,17 @@ ZigbeeFrame DLLN3X::recv(bool non_blocked)
 bool DLLN3X::send(ZigbeeFrame zf)
 {
     bool status = false;
-    if (zf.getSrcPort() < 0x80)
+    uint8_t len = zf.size();
+    if (zf.getSrcPort() < 0x80 || len > 66)
         return false;
-    status = _DSerial->write(zf.data(),zf.size());
+    status = _DSerial->write(zf.data(), len);
     return status;
 }
 
 bool DLLN3X::send_cmd(uint8_t des_port, uint8_t arg, uint8_t* data, uint8_t data_length)
 {
     ZigbeeFrame zf(0x80, des_port, 0x0000);
-    if (data_length - 4 > 63 - 1)
+    if (data_length + 4 > 63)
         return false;
     zf.append(arg);
     zf.addData(data, data_length);