Abstract: Under the mining condition of U-type ventilation and spontaneous combustion coal seam, the air leakage in goaf may create an environment with explosion hazard due to the mixing of oxygen and gas. Through the observation by embedding methane and temperature sensor in the goaf, the Fluent method is used to perform analog computation on gas distribution regularities of goaf, and the possibility of gas combustion in the dangerous area of spontaneous ignition is analyzed. Meanwhile, the hazard judgment and analysis is conducted on the explosion coupling area resulting from the interaction of gas and oxygen in the goaf, which provides the basis for field gas control.