Abstract: In order to study and analyze the impact of CO₂ injection at different locations, different CO₂ injection flow rates, and different temperatures on CO₂ fire prevention, the 8406 working face of Yangmei No.5 coal mine was selected as the research object. Based on the numerical simulation research, the Design Expert software was used for the Box-Behnken test design. A quadratic regression response surface model of the maximum width of oxidation zone in goaf under three factors and three levels was constructed. The maximum width of oxidation zone in goaf was predicted and analyzed. The results show that the maximumwidth of the oxidation zone decreases with the increase of CO₂ injection flow rate, and increases with the increase of CO₂ injection temperature; the P value of the quadratic regression equation is less than 0.000 1, which is extremely significant, and the missing fitting term is 0.253 7, which is not significant. The regression equation has statistical significance; when the position of carbon dioxide injection is 20-40 m, the flow of carbon dioxide injection is 720-1 080 m3/min, the temperature of carbon dioxide injection is between 278-288 K, and the order of the importance of the maximum width of the oxidation zone is CO₂ injection flow > CO₂ injection temperature > CO₂ injection position; the order of importance of the secondary terms is injection of carbon dioxide and position of injecting carbon dioxide>injection of carbon dioxide and position of injecting carbon dioxide temperature>injection of carbon dioxide and flow of carbon dioxide, and there is no interaction between the position of carbon dioxide injection, the flow of carbon dioxide injection, and the temperature of carbon dioxide injection. The optimal parameters are set as follows: CO₂ injection position is 30 m, CO₂ injection flow is 900 m³·min-1, and CO₂ injection temperature is 283 K.