Standby unloading device for railway train wheel set flaw detection system

The invention discloses a standby unloading device for a railway train wheel set flaw detection system. The standby unloading device comprises a jacking mechanism driven by a hydraulic system, a main oil pump and a manual oil pump, wherein the main oil pump is connected with the hydraulic system through a first hydraulic pipeline to be used as a power source of the hydraulic system; and the manual oil pump is connected with the hydraulic system through a second hydraulic pipeline to be used as a standby power source of the hydraulic system. When the main oil pump is stopped, source power can be provided for the hydraulic system through manual operation of the manual oil pump. Due to the arrangement, the standby unloading device for the railway train wheel set flaw detection system disclosed by the invention can unload wheel sets in the jacking state under the condition of sudden power failure.