Abstract: In order to effectively predict the gas explosion hazard at a fire region in closed working face due to coal spontaneous combustion in high gas coal mine,in the first place,the variation laws of methane and oxygen concentra- tion of the closed fire zone in a short period were deduced using the law of mass conservation. Afterwards,the accumu- lation models of methane and oxygen (AMMO) in the closed fire were constructed,the variation law and critical influ- encing factors of gases concentration were analyzed in the fire region,and then the hazard of gas explosion at the closed fire zone was discussed based on time intersection theory. In addition,the gas explosion hazard of a closed working face in a certain coal mine was estimated using the (AMMO) model,the possibility and occurrence time of methane explo- sion were obtained,respectively. Eventually,the gas explosion accident in the closed fire region had been successfully avoided because of appropriate and prompt preventive measures taken.