Based on the basic principle of strain energy,we establish the framework wharf three-dimensional finite element model and calculate the structure strain energy in the condition of flexible work of five kinds of impact forces.The results show that the main force transmission route of horizontal force along the transverse of the wharf is from the direct stressed component to the adjacent transverse components,and then the front row or back row pile foundation.The main force transmission route of horizontal force along the longitudinal direction of the wharf is from the direct stressed component to the longitudinal components closest to the acting position.The structure stores the maximum strain energy when the impact force is applied to the high water level，therefore it is proposed to check the structural stability in high water conditions;The strain energy of the peripheral components are larger，especially the front row or back row pile foundation,river-side transverse members and longitudinal member connected with the back pile.In other words,the force mainly passes through the peripheral components of wharf structure，and these components should be designed as the control components.