During shock wave propagation in the pipeline, the flow field of speed, pressure and temperature is evenly distributed. If there are obstacles, then the flow will be changed while the velocity gradient is formed near the obstacles. Passing through the obstacles, a high-speed gradient of the unburned methane mixture flow is established. While reaching the obstacle, the shock wave surface is rapidly stretched to increase the significant transmission speed. Propagating in the gradient field, the shock wave will be stretched and folded. The deformation of shock wave causes consumption of fuel and oxygen in greater unburned methane surface, which results in heat release rate increasing and faster shock propagation. In conclusion, shock wave causes larger advection speed in front of the unburned methane mixture, increasing flow velocity gradient further and leading to more intense shock wave propagation.