Hydrogen blended into natural gas transport in a certain proportion is gradually becoming the future development trend, the venting system as an important part of the station, it is necessary to study the concentration distribution of hydrogen-doped natural gas after the station venting and the range of combustion and explosion. Firstly, the changes of physical parameters of hydrogen-doped natural gas are analysed, the density of the gas mixture decrease, the diffusion and uplift tendency increase, the calorific value decrease, the explosion limit becomes wider, and the risk of ignition and explosion increase; then based on the simulation of PHAST software, the effects of the ratio of hydrogen-doped natural gas and the ambient wind speed on the scope of the gas diffusion, the scope of the influence of thermal radiation and the scope of the damage of the shockwave after the station venting are analysed. The results show that the hydrogen doping ratio increases, the gas diffusion range and shock wave damage range increase, and the maximum thermal radiation intensity and thermal radiation influence range decrease; the ambient wind speed increases, the gas diffusion range and thermal radiation influence range increase, and the shock wave damage range slightly decreases. The simulation results can provide a reference for determining the safety distance after hydrogen doping in natural gas station sites.