Abstract: The coal cleaning system of Huayuan Mine's Coal Preparation Plant used to operate with a low capacity and efficiency and a high medium consumption due to ever-increasing rise of proportion of fine coal in raw coal treated. To cope with this situation, work is made on technical transformation of the existing coal cleaning system based on result of analysis of the system. The technical measures adopted include renovation of working medium splitter box, addition of stacked high-frequency vibrating fine screen, fine coal dewatering centrifuge, magnetic separator and improvement of medium recovery system. Practice shows that the technical renovation work has led to improved separation accuracy of the primary heavy medium washing system, elimination of the need to make the ash of the system's clean coal to be lower than necessary, reduced ash of coarse slime and drop of both comsumption of medium and moisture of products, increased clean coal yield and improved composite economic performance.