The effect of the xtractsantioxidants 2,6butylatedhydroxytoluene (AO1) and p,p’diisooctyldiphenylamine (AO2) on the hyperchromic of aero lubricating oil (poly αolefin as the base oil) under harmful metal catalysis was investigated. The oil samples were extracted with methanol, acetone and ethyl acetate under the ultrasonic radiation, respectively. The chemical composition of the compounds in the methanol extract was analyzed by FTIR and GC/MS. The colordeepening mechanism of oil sample was speculated. The results indicate that metal and antioxidants play the key roles in causing structurechange to color deepening of oil. Although the antioxidants could postpone the hightemperature oxidation deterioration of the oil, their own structures were easily broken to generate multiple chromophores and auxochrome, such as ketones, amines and quinones, which would lead to the color deepening of oil. The reactions became even more violent with metal catalysis in oil. The compounds of ketones, quinones and amines, including hexanaphthene2,4dienone, 1,4benzoquinone, 2,6ditertbutylpbenzoquinone, 2,6ditertbutyl4methylenehexanaphthene2,5dienone and 4tertiarybutyl2,6dimethyl phenyl acetate, 1(pyridin3yl)ethanone, 1(2,7,7trimethyl4,7dihydrobenzo furan4yl)ethanone and other compounds, were believed to deepen the color of oil.