Abstract: A swift and efficient FE-PSBFE coupled elasto-plastic numerical method is proposed. The octree discretization technique is combined, and the hexahedrons are modelled using isoparametric element as in FEM while the PSBFEM is adopted to solve the other polyhedrons. In this manner, the problems including the difficulties of modelling, time consuming and laborious are eliminated in complicated geotechnical engineering structures. The precision and validity are verified using the simulation of a typical standard dam. Subsequently, a more complicated core wall dam is modelled using the FE-PSBFE coupled method, in which the flexibility, versatility and high efficiency are investigated. Compared with the traditional FEM, there are two primary superiorities that can be revealed:the process of modelling pretreatment can be accelerated dramatically, and the discretization problem considering the shape of complicated three-dimensional valley, layered construction and material partition simultaneously is eliminated, resulting in only few minutes expended in the discretization of hundreds thousand elements. Compared with the PSBFEM, the efficiency of elasto-plastic analysis can be improved significantly using the coupled FE-PSBFE, where more than 80% computation time can be saved. The FE-PSBFE method possesses satisfactory versatility in other complicated engineering geometries. The method can serve as a technological means for a swift elaborate seismic analysis.