Abstract: In order to solve problem of poor control effect of artificial or PID method because of coupling of three parameters including suspension density, content of magnetic medium and liquid level in dense-medium separation process, the paper proposed a fuzzy control method for multi-parameter in dense-medium separation process on the basis of analysis of dense-medium separation process. The method uses two fuzzy controllers to control liquid level and suspension density separately, and calculates dividing water quantity and filling water quantity combing with slime content according to defuzzification results of output of the two fuzzy controllers, so as to control opening degrees of dividing box valve and water valve. The industrial testing result showed that the fuzzy control method has higher stability, faster responding and smaller overshoot than traditional PID control method.