Abstract: Regarding the experimental conditions for low temperature oxidation of coal samples,field conditions of ventilation and face geometry in face gob,using similar criteria,this paper established the mathematical model of CO emission prediction in gob based on the experimental conditions,and applying the model the site face.Spontaneous combustion of residual coal in gob has related to air leakage.Through the numerical simulation of leakage airflow field in goaf of Beizao mine 4402 face by using FLUENT software,the paper calculated the air leakage resulting spontaneous combustion of residual coal in gob,which provided the condition for applying model to predict the indication range of CO emission accurately in site gob.