The relation between the porosity,nonuniformity coefficient,curvature coefficient and permeability coefficient was analyzed by changing the fine particle content. The relationship between the gravel soil permeability coefficient and porosity feature parameters was discussed. The gravel soil permeability coefficient and three pore characteristic parameters of multivariate regression model were established. Research results show that gravel soil coefficient of permeability and the three pore characteristic parameters is comprehensive,the individual parameters' influence on the permeability coefficient is random; 40% of the fine particle content can be used as the boundaries of the coefficient of permeability of sand gravel content,when the fine particle content higher than 40%,the permeability coefficient decreases smoothly along with the increase of fine particle content; When the fine particle content is less than 40%,the permeability coefficient decreases rapidly along with the increase of fine particle content. Only using the same skeleton structure characteristics of the soil could meet the consistency change law of permeability coefficient.