The invention relates to an auxiliary mounting tool for an operation mechanism. The auxiliary mounting tool for the operation mechanism comprises a base, a containing platform used for containing theoperation mechanism is arranged on the base, and the base is further provided with a driving mechanism used for driving the containing platform to move in at least two directions of the left-right direction, the front-back direction and the up-down direction relative to the base. The containing platform is driven by the driving mechanism to move in two directions of the up-down direction, the left-right direction and the front-back direction, and then alignment and installation between an output shaft of the operation mechanism and an assembly hole are achieved, additional force application isnot needed, a large amount of manpower is saved, the installation efficiency is high, and operation is easy.