In order to make Tingkou reservoir filter material economic reasonable,the paper based on the basis of gradation envelope of field soil aggregate according to filter soil retention and permeability requirements step by step to calculate the first layer of filter sand and the second layer of gravel filter material gradation envelope and in accordance with the principle of handy reclaiming.According to the too large difference between the original design of the first layer anti sand filtration and ascertaining gradation difference,the paper chose Yang Ling sand and Xianyang sand to test and analyze. Yang Ling sand was taken as first layer filter; aimed at the problem of gravel filter being too coarse, it used the method of mixing Yang Ling sand to adjust grading so as to let it approach the derivation of envelope,and took contact erosion test to check the rationality of filter layer gradation.The results showed that the adjusted gradation of anti filter material is more secure and is in accordance with engineering practice.