Provided is a beam -pumping unit motor adjusting device includes: preceding base, lock nut, slide rail, slide, rubber sleeve, back base, fixed cover, centibar, afterburning pole. Perpendicular connection of both ends of two slide rails and back base of beam -pumping unit motor adjusting device, rubber sleeve is established to two slides covers between slide and the slide rail on the slide rail, the left end of going up the slide rail is equipped with the external screw thread, base before overlapping, lock nut locking is passed through on left and right both sides, the center of back base is equipped with fixed cover, fixed cover endotheca has the centibar, the centibar left end is connected with the central screw hole in the lower part of the right slide, the centibar right -hand member is equipped with afterburning pole. The utility model discloses change motor or adjustment belt " 4 lines " convenient operation, time saving and labor saving, originally, there were two people (b) (b), 30 (b) (b) (b) (b) 60min (b) (b) to accomplish the operation, alone (b) (b) 5 (b) (b) (b) (b) 10min (b) (b) can accomplish the operation now, shorten and stop the well time, avoid the sand card, the thick well polished rod of oil slowly down, the emergence of production troubles such as wax card, and the operation cost is reduced, the crude oil yield is increased. (B, )