In order to solve the problems of limited conditions, low training efficiency and long training cycle in the current ship equipment maintenance training, a ship equipment virtual maintenance training system based on Unity 3D is designed, and the key technologies are studied. The 3D models of equipment, training scene and maintenance resources are constructed by 3DS MAX, and the model database is optimized based on component modeling and instance reuse. The logic simulation analysis and design are carried out, and the equipment operation logic simulation method is proposed; Through the fault tree tool, the description model of fault phenomenon, fault source and the relationship between them is established. The results of operation practice show that the system has good operation convenience and portability, which can improve the training quality and efficiency of trainees, and provide a useful reference for the subsequent development of similar systems.