Research purposes: The sand embankment has been growing concern in high class highway engineering construction over plain area to solve the difficult problem of high quality subgrade filling absence. The slope stability is one of the key factors in sand embankment design and construction. Based on Shear Strength Reduction Method (SSRM )，a sensibility analysis of embankment cross-section geometry size and filling material properties for sand embankment slope stability has been carried out.Measures to increase sand embankment slope stability were put forward to provide reference for expressway engineering construction.