Abstract: In order to solve the problem of low processing ability and poor separation effect of three product dense medium cyclone in Renjiazhuang coal mine coal preparation plant,the transformation conducted on the main equipment of 3LNWX1200 /850 three-product dense medium cyclone. On the basis of original cyclone,designed the JUW3 × 1200 /890 gravity-fed three product dense medium cyclone,and it has been put into operation. This new cyclone obtained good application effect,effectively solved the problems of low processing ability and poor separation effect in original equipment.