Abstract: With the increase of mining depth, the rise of sulfur content of raw coal has become a major bottleneck that restricts the improvement of economic performance of general coal preparation plants. How to optimize the washing process and reduce sulfur content of coal products has become a pressing problem calling for urgent solution by coal preparation plant. It can be concluded through float-and-sink analysis and laboratory test on separation of Yangquan anthracite using cyclone that: the sulfur content of the product can be effectively reduced while maintaining the generation of less amount of secondary slime when the size of the feed is reduced from 15 mm to 9 mm; and in the case of using H. M. cyclone to treat the ＜ 13 mm raw coal, comprehensive consideration needs to be given to the required indices of yield and sulfur content of the cleaned product, and the separating density should be controlled at 1.38 g/cm³.