Antioxidants were baked at high temperature, and the heat resistance of antioxidants were evaluated by mass loss and thermogravimetric analysis. Microstructure analysis of samples that before and after heat treatment were carried out by using infrared spectroscopy, ultraviolet spectroscopy and high performance liquid chromatography. Thermal stability of hindered phenolic antioxidants(A, B, C, D),phosphite antioxidants(E, F) and thioester antioxidants(G, H) were investigated. At the same time, the influence of common antioxidants on the heat resistance of HAA system were studied by the application of antioxidants in the powder coatings, which provided a reference for optimizing the high temperature yellowing resistance of HAA system powder coatings.