Tests of the soil column and the dynamic adsorption process of NH+4-N which used the soil sample nearby certain municipal landfill and the landfill leachate in the municipal landfill had been done and obtained the isothermal adsorption law of NH+4-N which fit Freundlich model, a series of important parameters such as dispersion coefficient and the mathematical model considered adsorption and degradation terms was build.Using large finite element software to conduct numerical simulations about NH+4-N in the cylindrical region which was 1.5m depth direction and radius of 0.5m and obtained the NH+4-N, migration and diffusion regularity in first, 3rd, 5th, 10th, 15th year in the surface soil which had continuous source and the results will base on the reseach of migration and diffusion regularity of NH+4-N in the aquifer.