This railway power supply inspection system is installed on the operating EMUs and electric locomotives to realize the full coverage of catenary and all-weather dynamic inspections and record real-time catenary and pantograph dynamic data to finish the inspection of onboard catenary, including dynamic geometrical parameters, No. of arcing, arcing time, arcing frequency and temperature anomaly. It can quick locate the position of malfunctions, reduce the onboard catenary breakdown time and increase railway operation efficiency.