In order to safeguard the normal operation of radars and ensure that these expensive facilities could achieve expected benefits within the 20 years of the life cycle of CINRAD, a fault diagnosis system was developed, which includes the hardware test platform and corresponding software. The former requires the establishment of a complete performance test platform, and the latter requires the development of a fully functional test procedure, so as to quickly and accurately control the instruments, meters, and test equipment, and achieve the rapid analyzing, processing, storage, and display of test data. Through real tests, the reliability, availability, and operability of the system are discussed.