Abstract: The residual coal in the goaf is oxidized in the air leakage environment and gradually forms weathered coal, the macroscopic morphology and microstructure of weathered coal are different from that of raw coal, and the ambient oxygen concentration of weathered coal also changes from time to time. Therefore, in this paper, the temperature programmed system is used to simulate the auto-thermal oxidation process of weathered coal, and the variation laws of CO concentration, C2H4 concentration and intersection temperature during the oxidation and heating process of weathered coal under variable oxygen concentration are analyzed; the characteristic temperature and thermo-gravimetric rate of weathered coal under variable oxygen concentration were studied by thermo-gravimetric analyzer. The experimental results show that the gas concentration released by weathered coal in the process of oxidation and heating up is always higher than that of raw coal, and the intersection temperature and the critical temperature from slow oxidation to accelerated oxidation are always lower than that of raw coal; the lower the oxygen concentration, the smaller the gas concentration and thermal weight loss rate released by weathered coal and raw coal in the process of oxidation and heating up, and the higher the intersection temperature, the critical temperature from slow oxidation to accelerated oxidation and the maximum weight loss rate temperature; compared with raw coal, weathered coal is more sensitive to the change of oxygen concentration and has a higher risk of spontaneous combustion.