we took an indoor one-dimensional soil column seepage experiment based on the soil sample in the shallow layer drilling of Hengshui groundwater science test field, and tried to probe the control mechanism of cohesive soil to saltwater migration and transformation by means of geochemical simulation. The results show that the cohesive soil has some barrier effects on the salt water migration; the blocking effect of soil column No. 1 on the Na+is dominated by adsorption, while that of soil column No. 2 on the Na+is mutual influenced by adsorption and cation exchange. The salt rejection rates of soil column No. 1 and No. 2, R₁and R_2, are 49. 8% and 54. 5% respectively. The retardation factors of two soils columns are 1. 54 and 3. 78 respectively; In the process of salt water migration, the main factors to control water-rock interaction are salt precipitation, the dissolution of gypsum and calcite, and the ion-exchange among Mg²⁺, Ca²⁺and Na⁺.