In order to explore the gas adsorption characteristics of CO2 outburst mining area, taking the second layer coal sample of Jinhe Coal Mine in Yaojie Mining Area of Gansu Province as the research object, the isothermal adsorption experiment of CH4 and CO2 gas in coal was carried out to analyze the adsorption characteristics of outburst coal. The results show that the Langmuir model is not suitable for the adsorption behavior of CO2 on coal, and the D-A model based on micropore filling has the best fitting effect on CO2. The research results will further enrich the basic theory of CO2 outburst disaster prevention and control.