Abstract: For Chengzhuang coal preparation plant, to slove the problem of the single-link control system of Medicament accession and the inexact amount of Medicament accession during slime water treatment process，a Collaborative Control System was designed based on fuzzy expert system in the Medicament process of thickener and filter press。The input of system is the overflow concentration of thickener and the dewatering model of filter press，and a fuzzy Controller was designed to compensate the additive amount of the two subsystems，which was to ensure the further improvement of aggregative indicator of economy, Processing speed and processing effect.