Abstract: In view of low maintenance efficiency and long cycle caused by insufficient on-site maintenance knowledge and professional guidance for mine-used equipments, and virtual reality and augmented reality technologies are generally realized on head mounted device, mobile phones or tablet computers with good mobility, but users can only rely on interactive handle and touch screen to interact, and visual experience lacks authenticity, a maintenance guidance system of mine-used equipments based on mixed reality was designed. Based on Unity3D virtual reality platform, the system adopts mixed reality device HoloLens to real-timely display maintenance instruction schemes, which realizes functions of virtual simulation of mine-used equipments principle, equipments management based on QR code, equipments maintenance guidance and remote expert collaboration. HoloLens visually presents maintenance instructions to maintenance personnel through virtual text, virtual device models, animations and voice prompts. Maintenance personnel can interact with HoloLens through line-of-sight tracking, voice interaction and gesture recognition. Application example of shearer gear wear fault maintenance guidance verifies practicality and effectiveness of the system.