Abstract: The composite lipid collector was composed of methyl oleate (MeO), methyl laurate (MeL) and amyl benzoate (nAB) according to the mass ratio. The flotation effects of different types and amounts of composite lipid collectors on low-order long-flame coal were studied. The microscopic interaction mechanism between different types of composite collectors and low-order long-flame coal was investigated by molecular dynamics method. The results show that compared with traditional kerosene collectors, the composite lipid collector can significantly improve the floatation efficiency of low-rank long-flame coal, and the flotation efficiency of ternary composite MeO/MeL/nAB collector is significantly better than that of binary composite MeO/nAB or MeO/MeL collector at the same dosage. The adsorption mechanism of different lipid collectors on the coal surface was revealed by molecular dynamics simulation of the adsorption configuration of the collector and the interaction between the collector and the coal surface. Compared with the binary composite collector MeO/MeL and MeO/nAB, the interaction between the terpolymer collector MeO/MeL/nAB and the coal model was stronger, and the flotation effect of low-rank coal was better.