The invention discloses a grounding device for power device maintenance. The device comprises a device metal shell connecting end, a wire and a grounding plate. The device metal shell connecting end comprises a fixed suction cup used for fixing the device metal shell connecting end to a device metal shell, a copper rod mechanism used for being electrically connected with the device metal shell, and an insulating support used for supporting the copper rod mechanism. A cavity is formed in a copper rod of the copper rod mechanism, and the conductive fluid is arranged in the cavity and leads to the contact face of the copper rod mechanism and the device metal shell. According to the present invention, the lossless electric connection between the copper rod mechanism and the device metal shellis directly achieved, the devices are not damaged, and the grounding device can be repeatedly used and is particularly suitable for the temporary grounding during device maintenance.