With the development of the railway industry getting faster and faster, the quality and efficiency of railway vehicle maintenance and repair also put forward higher requirements. Micro-industrial endoscopy is a visual inspection method for quality control in areas where human eyesight can not be directly observed in special environments such as the interior of containers, pipes, non-detachable equipment, and small gaps. Technology and lighting technology will be detected objects reflected on the display for inspection personnel reference. With the continuous development of high-speed railways, endoscopes are also used for more endoscopic detection of various high-speed railways and domestic CRHs in foreign countries. From TGV to ICE, from Changchun Bus Depot to Qingdao Sifang, from Dalian to Zhuzhou, endoscopes show the indispensable importance in gearbox detection, ventilation system and internal casting of high-speed trains.