The dynamic stress, dynamic shear modulus, dynamic shear modulus ratio and damping ratio of silty sand with different content of fine particles were studied by GDS dynamic triaxial test system. Considering the asymmetry of hysteretic curve in dynamic process, the dynamic parameters are solved by piecewise equation. The results show that repeated freeze-thaw cycles have a great influence on the reduction of dynamic stress, dynamic shear modulus and dynamic shear modulus ratio, and increase the damping ratio. Therefore, a normalized empirical model describing the relationship between dynamic shear modulus ratio, damping ratio and dynamic strain is established. The model is suitable for different fine particle content and freeze-thaw times, and can give good prediction results. Furthermore, the evolution process of model parameters with experimental conditions was further analyzed, and the critical value of fine particle content was determined to be 10%. After repeated freezing and thawing, the influence of fine particle content on parameters a and c was weakened. The regression relationship between model parameters and experimental conditions can be described by binary quadratic equation. It is suggested that the soil parameters after 5 freeze-thaw cycles should be used in the dynamic response analysis of silty sand.