Abstract: To improve products quality of fines separated by RC coarse slime separator and control clean coal quality effectively in Xinyuan Mine Coal Preparation Plant,classification effect of FXJ350 hydrocyclone was analyzed by contrast with FXG710 and separation effect of RC separator was analyzed by contrast with TBS. The results show that first-stage hydrocyclone underflow carrying too much fine slime affects separation of coarse slime directly. It is suggested to control products ash that flotation machine is preferred for separating fine slime and fines content into coarse separation system is reduced as far as possible.