The invention discloses an improved type device for regulating the driving force of a coating roll, which comprises the coating roll, a rolling bearing, a bearing seat, a regulating wheel, a sliding seat, a flat key, a power chain wheel, a frictional piece and screw threads, wherein the left side of the coating roll is in sleeve joint with the rolling bearing, the coating roll is matched with the bearing seat in a rotary way by the rolling bearing, the power chain wheel is sleeved on the coating roll and is matched with the coating roll in a movable way by the rolling bearing, the left side of the power chain wheel is connected with the sliding seat, the sliding seat forms the rotary or immovable matching of right-and-left sliding with the coating roll by the flat key, the right side of the sliding seat is matched with the power chain wheel in a frictional way by the frictional piece, the left end of the coating roll is connected with the bearing seat, and the regulating wheel is matched with the coating roll in a right-and-left regulating way by the screw threads at the left end of the bearing seat on the coating roll. The problems of easy slippage and generation of non-uniform pressure are solved, so that the driving force of the coating roll is constant.