Abstract: The jigger discharge system has significant nonlinearity,and the coupling relationship between parameters is complex.It is difficult to control the discharge process through a simple mathematical model,so there is a significant time delay in the actual change of discharge quantity.In order to deal with the above situation,a fuzzy cascade PID control method for quantitative discharge of jigs in coal preparation plant is proposed.According to the composition of the jigger discharge system,the gear and rack structure are designed,and then combined with the targeted force analysis,the fuzzy cascade PID controller is designed,so as to complete the self-tuning operation of the fuzzy rule base and control parameters,and realize the design of the jigger quantitative discharge fuzzy cascade PID control method. The experimental results show that the control based on the fuzzy cascade PID principle can adjust the feeding speed combined with the coal particle size and density,and realize the original intention of controlling the jigger discharge process with a mathematical model.