For problem of big overshoot of PID algorithm used by heavy medium coal preparation system which has characteristics of strong coupling, nonlinear and multivariate, the paper presented a control method with CMAC and PID algorithm. Through researching dynamic characteristics of medium density and liquid level of medium bucket, it established mathematical model of heavy medium coal preparation system and gave control principle with the CMAC and traditional PID algorithm. The Simulink simulation result showed that the control method is better than traditional PID algorithm, and has good dynamic performance and high stability level.