Abstract Aiming at the alarm fault of antenna dynamic error for CINRAD/CB radar,combined with the working principle of radar servo system,this paper analyzes signal flow between RDA computer and servo system,alarm judging method and system data file.The cause of the fault is determined and the fault is eliminated.The reason for the failure is that the RDA computer did not receive the corresponding return information within the specified time after issuing the command to raise the elevation angle,which results in the system alarm.