Abstract: In order to improve the efficiency of crushing coal and reduce the wear of liner, the influence of grinding parameters on the comprehensive benefit of production was studied based on discrete element method (DEM ) and Box-Behnken response surface method. The mathematical model of the regression equation between the diameter of the grinding ball, the inclination of the lining plate, the rotation rate and the comprehensive benefit of the production is established. The R² is 0.98, which is well fitted with the actual value, and the significance of the influence of the crushing parameters of the coal mill on the comprehensive benefit of the production is determined. In the interaction term, the diameter of the grinding ball and the inclination of the lining plate have the most significant influence on the comprehensive benefit of the coal mill. The best crushing parameter is that when the rotation rate is constant, the diameter of the grinding ball is 30 mm, the inclination angle of the liner is 57°, and the grinding efficiency of the coal mill reaches the maximum. The verification experiment of the predicted response value shows that the average error value is 3.63%, which confirms the accuracy and credibility of the model. It can provide more scientific guidance for improving the crushing efficiency of the coal mill.