Abstract: Following an analysis of the property of the coal slime of Limin Coal Preparation Plant of Wuhai Energy Co. Ltd., the present status of the secondary flotation-secondary dewatering process currently applied as well as the problems encountered, an improved technical process which works according to carrier flotation principle is proposed on basis of the above-mentioned process. It is designed to improve the secondary flotation system′s feed size composition by diverting part of the concentrate products from the 3rd and 4th cells of the primary flotation system into the feed of the secondary flotation system. Practice shows that after optimization the yield of flotation concentrate is increased by 8.98 percentage points with an ash of about 11.48%.