In order to improve the ability of Kaifeng city wall to resist environmental erosion， sodium methyl silicate， lime and rubber powder were used as admixtures， direct shear test， capillary absorption test and scanning electron microscopy test were carried out on the samples of restoration soil with different mix proportion through orthogonal tests to optimize the mix proportion of the restoration soil. The results show that the addition of sodium methyl silicate， lime and rubber powder can effectively improve the mechanical property and water resistance of the restoration soil. The influence order of admixtures on the cohesion of the restoration soil is lime>rubber powder>sodium methyl silicate. The influence order of admixtures on the internal friction angle and water tolerance is sodium methyl silicate>lime>rubber powder. The optimum mix proportion of restoration soil is 2.0% of sodium methyl silicate， 5.0% of lime and 2.0% of rubber powder.