Abstract: Aiming at the sticking fault of nuclear gate valve, a fault diagnosis method of gate valve based on characteristic analysis of operation process variables is proposed. The operating process of gate valve opening and closing often contains fault characteristics and changing rules. Therefore, this method first uses Shannon entropy to measure the vibration signal power spectrum of gate valve opening and closing process, calculates the mean value of power spectrum entropy as the target process variable, analyzes the characteristic changes of target process variables under the condition of gate valve health and fault degree, and then divides the fault area and non-fault area for gate valve fault diagnosis. Finally, based on the nuclear gate valve experiment, this method is experimentally verified. The results show that this method can effectively diagnose the fault of nuclear gate valve, and has a certain fault prediction ability. Therefore, the use of this method can reduce the probability of nuclear facility accidents caused by the sticking fault of the gate valve, and at the same time, this method can be applied to the fault diagnosis of the gate valve in other fields.