The invention discloses a workpiece buffing device. A buffing box comprises a buffing area and a power transmission area. A driving gear and driven gears are arranged in the power transmission area. The middle of the driving gear is provided with a rotating shaft a in a penetrated mode. The lower end of the rotating shaft a is connected with a power output shaft of a motor. The upper end of the rotating shaft a is provided with a rotating dish a. The middle of each driven gear is provided with a rotating shaft b in a penetrated mode. The lower end of each rotating shaft b is arranged on a bottom plate. The upper end of each rotating shaft b is provided with a rotating dish b. The upper surface of the rotating dish a is provided with a pair of bench screws. The upper surface of each rotating dish b is provided with a stand roller. A grinding sleeve is arranged between the two stand rollers in a sleeving mode. A top plate of the buffing box is a movable cover. The middle of the inner surface of the movable cover is provided with a sleeve pipe. The inner part of the sleeve pipe is connected with a telescopic rod. The lower end of the telescopic rod is provided with a buffing wheel. A back side plate of the buffing area is provided with an air exhausting hole. The outer end of the air exhausting hole is connected with a scrap collecting box through a pipeline. Metal dust generated in the buffing process enter into the scrap collecting box through the air exhausting hole and the pipeline, and the environment is prevented from being polluted by the metal dust.