In view of the problems such as many functional groups on the surface of slime, poor floatability, low yield and large consumption of flotation reagents in a coal preparation plant in Xiaoyi City, a new collector B-H was developed, and two factor multi-level flotation tests were used to explore the optimal dosage of traditional collector diesel, new collector B-H and foaming agent sec octanol, and the floatability test of slime was conducted for the optimal dosage. The results show that when the ash content of flotation cleaned coal is about 15%, the optimal dosage of B-H collector is 700g?t-1, the dosage of secondary octanol is 250g?t-1, and the flotation cleaned coal yield is 80.42%; The optimum dosage of diesel collector is 1100g?t-1, the dosage of secondary octanol is 250g?t-1, and the flotation clean coal yield is 50.76%. Compared with conventional collector diesel oil, the new collector B-H has increased the clean coal yield by about 30% and the flotation perfection by about 18%, which improves the floatability of coal slime and meets the production requirements.