diff --git a/src/main/java/com/genersoft/iot/vmp/gb28181/transmit/cmd/impl/SIPCommander.java b/src/main/java/com/genersoft/iot/vmp/gb28181/transmit/cmd/impl/SIPCommander.java
index a9b64ca2..ee9b61af 100644
--- a/src/main/java/com/genersoft/iot/vmp/gb28181/transmit/cmd/impl/SIPCommander.java
+++ b/src/main/java/com/genersoft/iot/vmp/gb28181/transmit/cmd/impl/SIPCommander.java
@@ -146,6 +146,10 @@ public class SIPCommander implements ISIPCommander {
         builder.append(strTmp, 0, 2);
         strTmp = String.format("%02X", parameter2);
         builder.append(strTmp, 0, 2);
+        if ((combineCode2 > 0) && (combineCode2 <16))
+        {
+            combineCode2 = 16;
+        }
         strTmp = String.format("%X", combineCode2);
         builder.append(strTmp, 0, 1).append("0");
         //计算校验码