The invention relates to self-screening and refeeding device for a ball mill, pertaining to an auxiliary device of the ball mill. The device comprises a lining connected with a discharging hollow shaft. A cylindrical screen is connected with the outer end of the lining; a guide spiral inverse to the rotating direction of the ball mill is arranged on the inner wall of the lining; a shoving spiral inverse to the rotating direction of the ball mill is arranged on the inner wall of the cylindrical screen; a guide cylinder for coarse-material return is installed in the lining and the cylindrical screen; a refeeding spiral inverse to the rotating direction of the ball mill is arranged on the inner wall of the guide cylinder; a refeeding hole is arranged on the peripheral wall at the end of the guide cylinder. The device has a simple structure, the independent grading system and the refeeding system are substituted and the land occupation of the milling system of the ball mill is reduced; the investment is saved, the energy consumption is reduced and the probability of system failure is lowered.