Abstract: Due to the fact that it is difficult for hard-to-float fine coal to obtain qualified products in the flotation process, such as high clean coal ash content, low tail coal content. The particle size, the density composition and the coal flotation test progressive release were experimented in lab, analyzed the influence of flotation process and the floatability. Flotation process and flotation condition were researched by flotation tests, the result showed that the first flotation is hard to satisfy the demand of user, due to the high ash and low yield of the clean coal, low ash of the tail coal, so the secondary flotation process must be taken to get the qualified products. According to the secondary flotation. Under the conditions of similar feed and 10% of the clean coal ash, the result of secondary flotation process which included the yield of clean coal , the ash of tail and the faultless Index of flotation exceed the first flotation process，3.37%, 2.50% and 3.38%, respectively. The industrial application results, under the same concentrate ash and the same feed, showed that the result of secondary flotation process which include the yield of clean coal , the ash of tail and the faultless Index of flotation exceed the first flotation process，5.78%, 3.20% and 4.93%, respectively.