The invention discloses an electricity verification grounding operation method and device of a rail transit system. The device comprises a control module, a grounding module and a discharging module. The grounding module and the discharging module can be electrically connected between a contact net or a contact rail and a backflow rail of the rail transit system. A communication port which is in communication connection with a grounding management backstage system is arranged in the control module. An electricity verification loop and a control loop are arranged in the control module. The electricity verification loop can be electrically connected between the contact net or the contact rail and the backflow rail. The first output end of the control loop is electrically connected with the grounding control end of the grounding module. The second output end of the control loop is connected with the discharging control end of the discharging module. Electricity verification operation of the contact net or the contact rail is carried out through the electricity verification loop in the control module and, the control loop in the control module is used for controlling the grounding module and the discharging module to execute corresponding grounding operation. Thus, the safety coefficient and the operation efficiency of the electricity verification grounding operation of the rail transit system are highly improved.