Abstract: The chemical composition of fatty acids in monomer acid was determined by GC/MS. After the monomer acid sample was etherified by methanol, the relative contents of fatty acids in it were analyzed with GC/MS. Fifteen components (such as myristic acid, palmitic acid, oleic acid and stearic acid ) were identified. The analysis results showed that tetradecanoic acid content was 12.16%, hexadecanoic acid content was 8.51%, octadecenoic acid content was 25.53% and octadecanoic acid content was32.72%. The feasibility of using the monomer acid as lubricant additive in aluminium rolling was studied. The rolling oil performance was comprehensively evaluated by taking the following five performance indices: compatibility, lubrication, tribological property, annealing property and anti-oxidation. The results showed that the comprehensive effects of the additive were excellent.