Abstract: This is an article in the field of mineral processing engineering. Fatty acid collectors are widely used in the flotation of oxidized ores, and the molecular structure is an important factor affecting the flotation performance. To reveal the effect of the structural change of fatty acid collector on its reaction activity from the microscopic point of view, the relationship between electronic structure and properties of fatty acid collectors was studied by the density functional theory. The research results show that the oxygen atom in oleic acid molecule and oleate ion has strong reaction activity, which is the bonding atom of oleic acid interaction with oxidized minerals. The two oxygen atoms of oleate ion have similar chemical activity, and the density of states at Fermi level is higher than that of oleic acid molecule, which makes the activity of oleate ion much stronger than that of oleic acid molecule. The length of the carbon chain and the unsaturation of the alkyl have almost no effect on the density of states of the oxygen atoms in fatty acids, their effect on the properties of fatty acids is not through the action of carboxyl groups. The interaction energy between fatty acids and common metal cations is consistent with the decrease of their solubility product constants, and there is a good corresponding relationship between them. The research has certain theoretical significance and reference value for understanding the relationship between the structure and performance of fatty acid collectors and developing new fatty acid collectors.