In order to investigate the effects of oxidation temperature,time and metal catalytic oxidation on the performance of diesel engine oil,high temperature oven and oxidation tester were employed to simulate different oxidation conditions to study the changes of typical physicochemical properties and tribological properties of diesel oil before and after oxidation.The effects of different oxidation conditions on the oxidation process and performance of diesel engine oil were analyzed.The results show that the physical and chemical properties,oxidation resistance and tribological properties of diesel oil will deteriorate to a certain extent after high temperature oven test,but the change range is small,and the oxidation degree of diesel oil is still at a low level.Under the condition of catalytic oxidation,copper and iron catalysts greatly accelerate the oxidation rate of diesel oil and deepen the oxidation degree,and the anti-wear performance of diesel oil decreases significantly.It is shown that catalytic oxidation will not only affect the physical and chemical properties and oxidation performance of engine oil,but also accelerate the consumption of anti-wear additives and the change of tribological performance.