The utility model discloses a hoisting device for an on-load tap-changer of a transformer. The device comprises a base, a first vertical column, a second vertical column, a cross beam, a cross beam hand buggy and a lifting hook, wherein a plurality of screw holes arrayed in the same manner with screw holes in a connection flange for the original transformer body and the on-load tap-changer are formed in the base, and the base is detachably fixed at the position of the connection flange for the original transformer body and the on-load tap-changer via a bolt; the bottom end of the first vertical column is detachably fixed on the base, and the first vertical column is vertical to the plane of the base; the bottom end of the second vertical column is rotationally fixed at the top end of the first vertical column; the cross beam is detachably fixed at the top end of the second vertical column, and a slide rail is arranged on the cross beam; and the cross beam hand buggy is slidably fixed on the slide rail of the cross beam, and the lifting hook is fixed on the cross beam hand buggy. Compared with the prior art, with the adoption of the device disclosed by the utility model, the problem of difficulty in safe hoisting for the on-load tap-changer of an indoor transformer is greatly solved.