Abstract: In order to study the influence of flotation reagent system on coal slime flotation, the coal slime of Shuiyu Coal Washing Plant is taken as the research object.Based on the uniform experimental design(UED)method, the mathematical model between flotation effect and reagent dosage is established, and the effect of collector and frother dosage on flotation effect is investigated.The results show that the flotation effect of coal slime is only related to the amount of frother in a certain range of collector dosage; the optimal dosage of frother is 75 g/t, the appropriate dosage of collector is 130 g/t.Compared with the actual production dosage, under the conditions of 257 g/t collector and 143 g/t frother, and the ash content of clean coal kept unchanged, the yield of flotation clean coal is increased by 0.49 %, the combustible material recovery is increased by 0.50 %, the improvement index of flotation is increased by 0.17 %, the dosage of collector is reduced by 127 g/t, and the dosage of frother is reduced by 68 g/t.When the collector dosage is within a certain range, the frother dosage is the key factor affecting the flotation effect, and the appropriate frother dosage can significantly improve the coal slime separation effect.