Abstract: In order to overcome limitations of normal calculation methods, a meshless, Lagrangian particle method, namely Smoothed Particle Hydrodynamics (SPH) is applied to simulate the process of soil large deformation. Firstly, based on the theory of SPH, the formulations on elastoplastic mechanical governing equations are discreted. Meanwhile, the corresponding stress-strain relationship in SPH program is proposed and the transformation between stress-strain relationship and the movement of internal particles in soil is completed by using Jaumann stress rate. Subsequently, two groups of numerical simulation are conducted to verify the accuracy of the SPH method: 1) Numerical modelling of elastic simple shear test is carried out. Computed results are basically accordant to the analytical solution. 2) Numerical simulation of soil undrained simple shear test with large deformation is conducted. Computed results are validated by a comparison with the results of numerical simulation with the finite element method applying the modified Cam-Clay model. It has been proved that the SPH method can simulate the state of stress-strain relationship in soil large deformation analysis with high stability and accuracy. Therefore, this new computing method can be used in the research of numerical simulation of soil large deformation.