The invention discloses a method for reducing trans-fatty acid in high temperature oil and fat. The method comprises the following steps of adding carnosic acid oil, fat-soluble tea polyphenols, L-ascorbic palmitate and vitamin E in a certain addition sequence to vegetable oil and fat, or mixing the carnosic acid oil with the fat-soluble tea polyphenols, the L-ascorbic palmitate and the vitamin E to obtain a mixture, and then adding the mixture to the vegetable oil and fat. According to the method disclosed by the invention, a certain content of exogenous substances are added to the oil and fat, so that the oxidation resistant effects of edible oil can be notably improved, and the content of the trans-fatty acid in the oil and fat can also be reduced.