Because most servo components are in a longperiod mechanical operation, and the complex lines, the CINRAD/SA weather radar servo system failure rate has been high. Aiming at the heavy task and high requirement of newgeneration weather radar maintenance, it is proposed to realize the realtime control of the spare part status of the CINRAD/SA servo system by a testing equipment, so to reduce the uncertainty of the replacement servo components. The replacement can be used at the same time, while the fault spare parts can be repaired by the testing equipment, to further shorten the radar maintenance time, improve the availability of radar, and save the maintenance cost. The system composition, hardware and software design, fault diagnosis, and test method of the CINRAD/SA radar servo system testing tool are introduced.