Abstract: Soybean oil, rapeseed oil, peanut oil and lard were used as substrates for antioxidant experiments, and Lycium ruthenicum was extracted with 70% ethanol to study the antioxidant effect of the extract on oils. The results showed that the antioxidant effect of Lycium ruthenicum extract on the four oils was: soybean oil＞ lard＞ rapeseed oil＞ peanut oil, and the higher the concentration of the extract, the stronger the antioxidant effect. In the contrast experiments of Lycium ruthenicum extract with other antioxidants and added synergist on the antioxidant effect of oils, the antioxidant effect of the extract on lard is better than other antioxidants and the added synergist group at the same concentration. In addition, the acid value of four oils was measured, and the antioxidant mechanism of Lycium ruthenicum extract on oils was discussed.