The invention provides a subway vehicle operating recording device. Correlated points of traction and braking control circuits are used as recording points. With a magnetic coupling technique, all input loop crosstalk problems are isolated. A train control loop monitoring system has 24-path inputs for carrying out monitoring, tracking, and recording on direct-current voltages; an SD card is used for recording the voltage data; PC terminal management software reads data into a PC terminal through a USB port; and data measurement and analysis are carried out at a display interface of the software.