The work aims to quantitatively analyze the effect of anti-oxidation coating on the oxidation rate of S31254 super austenitic stainless steel during heat treatment by studying the characteristics of high-temperature oxidation. The oxidation weight-gained curve of S31254 super austenitic stainless steel at constant temperature was measured by thermogravimetric analysis experiment. The oxidation loss of specimen was investigated during annealing at different temperature, and the microstructure of the oxide layer in the longitudinal section of the annealed specimen was analyzed. The results showed that when the annealing temperature reached 1 300 ℃, the oxidation weight-gained curve of the specimen gradually changed from the original parabolic law to the linear law. The high-temperature oxidation loss of the specimen was serious because MoO3 was easy to gasify. When the annealing temperature was 1 220 ℃, the average single-sided oxidation loss rate of the specimen in air was about 4.0 μm/h. When the anti-oxidation coating was used, the average single-sided oxidation loss rate decreased to 3.2 μm/h. The protective effect of the coating was remarkable. The oxide layer formed in the process of annealing at 1 220 ℃ could be divided into two parts, which were the inner oxide layer composed of oxides of Cr and Fe and the outer oxide layer composed of oxides of Fe. The results illustrate that the anti-oxidation coating can significantly reduce the oxidation rate of S31254 super austenitic stainless steel at 1 220~1 280 ℃.