Taking Donghai bridge offshore wind farm as the background, this paper firstly calculates the displacement and excess pore pressure of multi-layer non-homogeneous soil based on Biot consolidation theory, and makes a discussion on the effect of wave load on the seabed motion; then, based on the displacement results, this paper obtains the internal forces and deformations of offshore wind turbine monopole by the dynamic p-y method and the support displacement loading method, and compares them with the results without seabed motion. It is illustrated that the seabed motion has appreciable impact on the deformation of pile shaft, therefore, it is recommended to perform the deformation check considering seabed motion.