Abstract: In order to improve the grinding efficiency of ball mills, a simple device of determining the impact crushing characteristics of ore is proposed and the characteristics data of the ore can be constructed based on the test results in this paper. Further, the performance of impact crushing and grinding of steel ball can be improved effectively by adjusting the normal component of the momentum between the ball and ore particles in falling and contacting moment. Research results show that data reflecting the impact crushing characteristics of the ore can be obtained conveniently via the device, and then the demanded impact crushing momentum for the ore sample can be confirmed. Appropriate steel ball size and mill speed can be confirmed conveniently according to the mill's chamber, and the comparatively ideal grinding efficiency will be obtained.