The invention proposes a steel ball impurity removing and classifying dual-purpose machine. The machine comprises a chassis, an impurity removing mechanism, a classifying mechanism and storage mechanisms; a first ball inlet is formed in one side of the top of the chassis; the impurity removing mechanism includes an impurity removing box, a rotating shaft, a spiral blade, a driving device and multiple polishing rods; a second ball inlet and a ball outlet are formed in the impurity removing box; the classifying mechanism includes multiple connecting rods, a ball guide plate and multiple roller shafts; multiple strip-shaped through holes are formed in the ball guide plate; the storage mechanisms are corresponding to the strip-shaped through holes one to one, and are mounted below the corresponding strip-shaped through holes; a material guide plate is rotationally mounted in the chassis, and is positioned between the connecting rods and the ball outlet; a discharge port is formed in the side wall of one side, corresponding to the ball outlet, of the chassis; and the discharge port is positioned between the ball outlet and the connecting rods. The machine can classify steel balls after impurity removal, also can singly perform the impurity removal and the classification for the steel balls, and only needs the driving device for driving the rotating shaft so as to effectively save electric energy.