Abstract: In order to study the influence of gas pressure on the propagation of coal and gas outburst shock wave, a set of coal-gas two-phase flow simulation experimental system was developed independently. The simulation experiments of coal-gas two-phase migration law under different gas pressure conditions were carried out, and the visual monitoring of coal-gas two-phase migration in the roadway during the outburst process was realized. The experimental results show that the coal and gas outburst is a dynamic process from the outburst to the interior of the coal mass, the gas pressure fluctuates up and down for many times during the period; during the outburst process, the overpressure of the shock wave in the roadway presents a pattern of alternating change positive pressure and negative pressure, and the characteristic value of shock wave overpressure increases with the increase of the initial gas pressure in a logarithmic function; the propagation of shock wave overpressure in the roadway is a process of constant attenuation. The attenuation is slow in the early stage and accelerates in the later stage.