Abstract: Effects of different grinding conditions on impact wear, abrasion wear and corrosion wear are systematically studied, and the influence of ball hardness and corrosion resistance of steel balls are considered. And the prediction model for the law of steel ball wear is established on the basis of theories and experiments. Differential evolution is then adopted to identify the parameters of the prediction model based on the ball wear data which are obtained by five different experiments in different conditions of grinding. Finally, the model is validated to be satisfactory with trial data. The variation of steel ball diameters can be simulated and predicted effectively, and the prediction model can be also used as a calculation basis in adding steel balls reasonably into the ball mill.