Abstract: For effective cleaning of the low-grade coal, in addition to introduction of the intensive screening technology with the use of flip-flop screen, an integrated cleaning system composed of 6-3 mm coal in-depth screening process, sized coal cleaning process, 3-stage slime thickening process is employed in Selian No.2 Mine Coal Preparation Plant. Following an in-depth analysis of the problems encountered in cleaning of the low-grade coal, as well as the raw coal property and product structure, a targeted cleaning scheme is proposed. Practice shows that: compared to the low-grade coal treated in the neighboring coal preparation plant, the yield of saleable coal is lowered by 14.03% yet its calorific value is increased by 2.15 MJ/kg; and more profit can be gained because of its advantages in calorific value and selling prices.