Abstract: The saline soft soil roadbed is easily subjected to poor engineering characteristics such as mud boiling, salt heave, frost heave and corrosion, so it is of great significance to study its mechanical characteristics. The indoor geotechnical tests are carried out, and four treatment schemes for saline soft foundations are put forward based on the on-site surveys. The dynamic characteristics of the improved saline soft soil and remolded soil are investigated, and the relationship between the dynamic shear modulus ratio and the damping ratio of the saline soft soil and the two types of improved saline soft soil with strain is compared and analyzed. The results show that the improvement of the bearing capacity of the roadbed by adding cement, lime and fly ash is better than that by adding sand gravel. The dynamic elastic modulus of the two kinds of improved soils significantly increase, and the improvement effect of cement lime fly ash on the dynamic characteristics of saline soft soil is obviously better than that of sand gravel.