Abstract: In order to solve the serious damage of coal resources, production equipment, ventilation system and atmospheric environment caused by coal fire disaster in the mine, the influence law of carbon dioxide on the spontaneous combustion characteristics of coal samples was studied in depth. The coal samples of Daliuta Mine were collected, and the change of characteristic temperature, exothermic energy and apparent activation energy of coal samples under different carbon dioxide concentration was studied by thermal analyzer. The experimental results showed that: with the increase of oxygen concentration, the sensitivity of coal sample characteristic temperature to carbon dioxide concentration decreases; the higher the concentration of carbon dioxide, the wider the distribution of the protective film on the surface of coal, the higher the thickness is, the different impact on the oxidation and heat release of coal is; the apparent activation energy of coal sample increases with the increase of the proportion of carbon dioxide concentration, and the sensitivity of the apparent activation energy and carbon dioxide concentration of coal is different. The injection of carbon dioxide into the coal sample effectively inhibited the occurrence of coal spontaneous combustion.