In order to study the dynamic process，damage of liquefied natural gas (LNG) leakage and diffusion(LNG), a Gaussian smoked mixture model with point source continuous leakage modified by Gaussian smoke group model was selected and programmed by MATLAB software to study different grounds. Half of the lower limit of the explosion(1/2LFL), the lower limit of explosion (LFL), and the upper limit of the explosion (UFL) corresponding to different factors, and the influence of the factors such as the effective height of the leakage source on the leakage of LNG gas and the analysis. And the experimental models were verified by Burro No. 9,The results show that the range of the danger area decreases with the increase of the surface roughness. With the increase of the effective height of the leakage source, the concentration of the highest point is decreasing and the danger is reduced at the same time. The scope of the area will continue to decrease.Due to the different wind speed, in the early stage of LNG leakage, the greater the danger area, the greater the wind speed. After the state of the gas cloud is stable, the area of the dangerous area decreases with the increase of wind speed.