Abstract: Aiming at the problems of low efficiency,long cycle and complex inspection process caused by insufficient technical ability and complex inspection process of underground mine. This paper designs an inspection system of underground mining equipment based on mixed reality technique. The system uses HoloLens Mixed Reality equipment,builds a virtual simulation development environment of mixed reality through Unity3D platform. The real equipment 3D model and standard maintenance opinion guidance database are established,and the patrol path navigation and equipment information management,equipment model display,maintenance opinion guidance and parts to be inspected are realized. This paper describes the framework design and function of the inspection system,summarizes the process of model establishment and key technologies. Taking the crusher of Yanqianshan Iron Mine as the study object,the comprehensive test of the system is carried out from the perspective of the coordination of user experience and system performance. The application results show that the system simplifies the tedious workflow of the traditional inspection,reduces the complexity of the inspection personnel′s work,effectively improves the inspection efficiency and has good man-machine interaction.