Abstract: Middling coal, which is mainly composed of coal gangue, is a very valuable and scarce resources, in order to recycle the scarce resources, first of all, coal and waste rock will be fully disintegrate. A new vertical crusher with two－stage crushing, whose can effectively reduce the middling coal crushing rate and improve the yield of clean coal, has been designed. To better understand the performance of the grinding machine, with its as the research object, the simulate of the working process of the grinding machine is carried out by using discrete element software EDEM. Using the number of broken bonding of middling coal as a measure of material crushing effect, the influence of different coarse crushing speed to broken bonding is obtained. On the basis, an optimal coarse crushing speed is selected, and the experimental prototype is trial-produced. On the test model, the accuracy of the simulation results is validated by the test of coarse crushing speed condition test. By the analysis, it is concluded that when the rough frequency is 50?Hz, the crushing effect is the best.