Abstract: A mathematical model of gas explosion in heading face is established in this paper.using fluid dynamics software FLACS to simulate roadway filled with different concentrations of methane gas and with or without barrier,the simulation results show that concentrations of methane gas and obstacles have a greater influence on pressure wave change in gas explosion process,the gas explosion pressure wave is not monotonic decay along the tunnel in propagation process,but there is fluctuation;when there are no barriers,the explosion pressure wave changes slightly;but with barriers,explosion pressure wave changes greatly and quickly.