In order to exclude a dynamic antenna fault of Guangzhou Doppler radar, the servo system is divided into four parts: machinery, amplifiers, communication link, and signal control to conduct failure analysis one by one. By using BDAVC5 to analyze the antenna running trajectory, it is found that the problem appeared on the control of antenna elevation, and the failure was excluded by replacing the analog board of the digital control unit. Through elaborating the process of failure analysis, the occasions that antenna dynamic faults may occur and preliminary identification methods are discussed. The ideas and methods that were used during the fault location process can provide a reference for the technical support of new generation weather radar.