Abstract: In order to study the grinding and wear law of the pendulum mill, based on the rocky DEM discrete element simulation, one-time grinding and total grinding simulation tests have been carried out. As the material layer changes and wear increases under actual working conditions, five groups of grinding roller and grinding ring gaps are set: the initial installed state (0 mm), the material layer state (3、5、8 mm), and the wear limit state (25 mm). Combined with the impact frequency and impact power spectrum analysis, the grinding efficiency and wear decrease with the increase of the gap, and the yield of one-time grinding is the key to obtaining efficient grinding. The yield of one-time grinding is 77.2%、53.1%、21.4%、6.1% and 1.7% respectively, and the yield of total grinding is increased by 1.3%、12.5%、7.6%、0.7% and 0% respectively. Under the actual working conditions, the working parameters of the mill should be reasonably matched to obtain the dynamic material layer thickness control. The design schemes of tyre type and round table type grinding rollers are put forward, and the round table type scheme is recommended based on grinding efficiency and wear index. The research results provide ideas for the theoretical analysis and optimization of the pendulum mill.