Abstract: Wushan Copper-Molybdenum Mine is the first domestic mining enterprise to use extra-arge semi-utomatic mill and ball mill.For many years- operation,the grinding process flow and equipment have been optimized.The SABC crushing and grinding process flow has been changed into SAB grinding process flow,increasing the treatment capacity and solving the problem of unstable process index such as grinding fineness distribution and grinding system feed;the steel ball fill rate in the mill is improved,the hard rock windows of the grid board in the semi-automatic mills are reduced,interval optimized ball-illing method is employed to fill steel balls,automatic control manner is used.The production practice shows that the equipment has been operating smoothly for last 3 years and the equipment function rate always keeps above 92 %.The grinding capacity already surpasses the designed capacity that is 15 %.The operation has achieved enormous economic benefits.