Abstract: Based on the theory of the soil hydro-mechanical coupling constitutive model, a chemical-hydromechanical coupling constitutive model (C-H-M model) of soil is proposed. In this model, the impact of salt and alkali ion solutes of the soil pore water on the preconsolidation pressure is considered by employing a chemical softening equation. A numerical simulation of the parameter in the softening equation is conducted on the basis of the experimental results. The C-H-M coupling constitutive model is validated by conducting a numerical simulation.