Abstract: Aiming at the fault ratio problems of internal defects, wear, damage and overload size in the use of the moving part, the roof and the pantograph of the EMU, the intelligent detection equipment for EMU operating state was set to the finished line of EMU depot. The equipment was used to collect the images of the bottom, side, and top of the running train in real -time, apply automatic fault recognition strategy to dynamically monitor the state of various parts related to the train, such as the running gear, the brake shoe, the bogie, the contact network, etc. According to the experiment and field use, this equipment meets the measurement requirements for the on-line measurement and detection of the running gear and pantograph in the running of railway locomotives. The measuring precision of the running gear can reach 1 mm, the measurement accuracy of the wear value of the slider can reach 0.2 mm. In view of this, this equipment can find the problems on time, provide the basis for maintenance and replacement, and ensure the safety of the EMU operation.