The invention provides direct-current electricity-checking grounding equipment and a working method thereof. The direct-current electricity-checking grounding equipment comprises a cabinet body, a direct-current electricity-checking device and a grounding device, wherein the direct-current electricity-checking device comprises a direct-current electroscope and a direct-current electricity-checking contactor which mutually adopt a convenient contacting and separating mode, the direct-current electricity-checking contactor is arranged in an inner cavity of the cabinet body; the direct-current electricity-checking contactor is electrically connected to a signal source circuit; the grounding device comprises a knife-edge base and a grounding knife which are connected in the convenient contacting and separating mode; the knife-edge base is arranged in the inner cavity of the cabinet body; the knife-edge base is electrically connected to the signal source circuit. And therefore, according to the direct-current electricity-checking grounding equipment and the working method thereof, the electricity-checking operation and the grounding operation are combined together to replace the conventional carrying type grounding line, so that the temporary maintaining and grounding operation of a contact net (a contact rail) is completed, the security of the maintaining staff is guaranteed, the workload is reduced, the working strength is lowered and the structure is compact. Moreover, the forced electricity-checking operation is ensured, so that the wrong operations are avoided.