In order to improve the efficiency of fault diagnosis of self-propelled gun, a fault diagnosis method of self-propelled gun based on fault tree analysis is proposed. According to the structure and characteristics of self-propelled gun, a fault tree model is established, and the operation status of self-propelled gun is detected by combining various sensors. The operation of the self-propelled gun is monitored in real time to ensure its reliable operation. The results show that this method is helpful to integrate the fault knowledge system of self-propelled artillery, so that maintenance personnel can quickly find out the fault, timely and reliably remove the fault, and improve the safety of self-propelled artillery.