The dynamic deformation and strength characteristics of fine grained soil in the super-deep overburden layer is the focus of engineers because soil buried deeply underground cannot be bulldozed easily.In this study，a series of dynamic triaxial tests is performed in silty sands buried deeply in the super-deep overburden layer foundation of an earth-rock fill dam，and the dynamic deformation and strength characteristics of soil in an earthquake zone are analyzed.The results show a strong linear relationship between the maximum dynamic shear modulus of testing soils and the mean effective stress of soils in the dual-logarithm coordinates system.The decay （increasing）curves of soil dynamic shear modulus （damping ratio）in various confined pressure conditions can be unified by the model of soil reference shear strain, and the decay （increasing）curves of soil in an arbitrary stress condition can be obtained through the extension of decay（increasing）curves of soil in testing stress conditions.The dynamic strength characteristics of testing soils is influenced by the density of soil and the testing stress condition；significant differences in the characteristic parameters of soil dynamic strength testing with various failure criteria are shown when the soil is the condition of unequal stress consolidation.