The invention relates to a bearing auxiliary replacement device, in particular to a cooling tower fan bearing auxiliary replacement device. The aim of the invention is to provide the cooling tower fanbearing auxiliary replacement device capable of bearing an impeller. The cooling tower fan bearing auxiliary replacement device comprises a mounting frame, a bearing seat and the like, and the bearing seat is arranged in the middle of the mounting frame. The impeller is borne, the effect of auxiliary mounting is achieved, a worker slides a shielding box towards one side, a transverse rod is inserted into a corresponding inserting hole, then the worker can disassemble a fan bearing, a buffer piece is driven to downwards move under the gravity effect of a rotating shaft and the impeller, thus the buffer effect is achieved, when the rotating shaft and the impeller need to be upwards lifted in the replacement process, the workers constantly steps on a pedal, then the rotating shaft and the impeller can be slowly lifted, replacement mounting work is completed in an auxiliary mode, the rotating shaft is guided through a guiding sleeve, and thus the rotating shaft and the impeller are prevented from skewing.