Abstract: To study the promoting function of nonionic surfactant in coal slurry flotation, the test was carried out with the combinative collector which is combined of SPAN80 and kerosene and using different sets of proportion and the dosage. The result shows: SPAN80 is able to improve the performance of collector significantly, increase the plant yield and tail coal ash content, and reduce the consumption of kerosene, it has a good technical and economic benefits as well; It is shows that the effect of SPAN80 as a catalytic to coarse grain is greater than that to fine-grained through particle size analysis of flotation product, whats more, the effect to +0.250 mm coarse particle is more obvious. Moreover, the promoting function mechanism of SPAN80 was studied, finding that SPAN80 produced emulsification for kerosene, changed the coal surface wettability and eliminated effects of the coal surface oxygen containing functional group. While the verifying test on the similar coal samples shows better flotation effect