For a detailed analysis of the internal force of wharf bents of multi-layer beam slab wharf berthing structure under the ships’ impact force，we use the 3D and 2D models to establish the finite element model for a comparative analysis.The result reveals that the calculation results of 2D model using the simplified method and that of 3D model have a great difference.This paper presents a method using the elastic supports’ simplified horizontal force，which agrees well with the 3D model structure.