Abstract: The environmental pressure has obvious influence on gas explosion. The simulation of gas explosion was carried out to analyze the pressure field, velocity field and temperature field by flow field platform under high pressure environment. According to the simulation results, the maximum explosion pressure increases exponentially with increasing of environmental pressure at the range of 2.0 MPa. With the increase of the initial pressure of the environment, the time of flame arrival is shorter, and the explosion temperature is increased. With environmental pressure increasing, the flame burning velocity is decreased and then increased within 20 ms, but the final state is consistent with different initial pressure.