Abstract: The ball mill system has characteristics of multivariable,strong coupling,large delay and great change of production condition,so it is difficult to achieve control goal when using common control strategy.To solve the problems,the paper proposed a design scheme of ball mill system based on fuzzy internal model control,analyzed working principle of ball mill and built its mathematical model.It introduced decoupling analysis of ball mill system in details,and gave design method of fuzzy internal controller of ball mill at last.The simulation result showed that ball mill system based on fuzzy internal model control has good decoupling ability and strong robustness and can solve the problems of time variation,coupling and delay of the ball mill system,which has engineering application value.