Taking a certain type of ball mill as the research object, combined with discrete element software, a numerical simulation model of the ball mill grinding media is established, and its reliability of this numerical simulation method is verified through a comparative test. Combined with the simulation method, by adjusting the inclination angle of the lining board, the corresponding motion characteristics of the grinding medium are obtained. Combined with the movement trajectory, the quantity distribution and the proportion change of different types of medium contact force, the variation characteristics on the motion characteristics of the grinding medium in the process of adjusting the inclination angle of the lining board are analyzed. The results show that: when the medium motion is adjusted by changing the inclination angle of the lining board during grinding, the smaller the inclination angle of the lining board, the better the lifting effect on the medium. When the inclination angle is between 75° and 90°, the proportion of the interaction force between the mediums remains at a high level, which grinding and crushing get better effects.