The utility model provides a protection cover used for an outdoor cabinet of a public bicycle system. An electrical appliance panel and a metal frame arranged around the electrical appliance panel are included in the outdoor cabinet. The protection cover comprises a cover casing covering the electrical appliance panel and a connection portion connected to the edge of the cover casing in an integrated mode. A plurality of steel magnets are arranged on the connection portion. The protection cover used for the outdoor cabinet of the public bicycle system is arranged in the outdoor cabinet and covers the electrical appliance panel, so that rainwater is thoroughly isolated from the electrical appliance panel, and a protection layer forms; accordingly, short circuit of the electrical appliance panel due to contact between the rainwater with the electrical appliance panel is effectively eliminated; safety hidden troubles are reduced; and normal usage of the outdoor cabinet is ensured.