The invention discloses a bale plucker which comprises an inner ring wallboard, an outer ring wallboard, a platform, a trolley, a cotton pipe, an expansion pipe, a cotton suction cover, a beater and a bracket, wherein a circular groove is formed in the upper end surface of the outer ring wallboard; the inner wall of the trolley is provided with a retention device formed by a baffle, a pulley and a sealing element; the top of the baffle is connected to the inner wall of the trolley by a transverse section; two convex parts extend from the lower part of the baffle; one of the two convex parts is arranged in the circular groove, and the pulley is fixedly arranged on the convex part; the other convex part is arranged at the inner side of the outer ring wallboard, and the sealing element is fixedly arranged on the convex part; the sealing element leans against the outer ring wallboard; the inner side of the baffle is an inclined plane. The bale plucker has the beneficial effects that the retention device is arranged between the inner wall of the trolley and the outer ring wallboard, so that a cotton layer which is about to overflow the outer ring wallboard due to the collision of the cotton suction cover in the platform moving process can be blocked by the retention device and is prevented from overflowing, the raw material waste is reduced, and the normal production of equipment can be guaranteed.