Abstract: The penetration process of spudcan in saturated soil concomitantly involves extremely large soil deformation and complex soil-water-structure interaction, which are difficult to simulate using traditional mesh-based methods due to mesh distortion. SPH is a mesh-free method by using a set of unrelated interpolation particles, and its governing equations (PDEs) are converted to ODEs and then solved. Thus, mesh distortion is avoided. Based on the soil-water-structure coupled SPH algorithm, the entire penetration process of spudcan into medium dense sand, dense sand and clay was simulated. The penetration resistance, excess pore water pressure and the total stress of soils undergoing large deformation were investigated. Subsequently, the calculated results were compared to the aftermaths of CEL (Coupled Eulerian Lagrangian) and centrifuge tests. It was proven that by adopting soil-water-structure coupled SPH methods, the penetration resistance, the pore water pressure and the excess pore water pressure could be satisfactorily captured. It was also true for the free surface of the soil-water mixture undergoing large deformation.