Electric leakage monitoring device and monitoring method of special return rail traction power supply system

The invention discloses an electric leakage monitoring device and monitoring method for a special return rail traction power supply system, and the device comprises a positive rail, one side of the positive rail is provided with a negative rail matched with the positive rail, and one side of the negative rail is provided with a grounding grid for protecting equipment and a human body. A monitoring device shell used for electric leakage monitoring is arranged between the negative pole rail and the grounding grid, a monitoring assembly used for monitoring and controlling is arranged in the monitoring device shell, and an electric leakage monitoring program is arranged in the controller. Through the design of the first connector, the second connector and the monitoring assembly, when leakage of the contact rail to the ground occurs, personal safety protection and direct current leakage fault alarm and selective removal are achieved through negative-ground voltage monitoring and main loop leakage current monitori