Using the finite element analysis software ANSYS, we establish a numerical model to simulate a new high-pile wharf in the fluctuating backwater area on the upper reach of the Yangtze River after the impoundment of the Three Gorges reservoir. Mechanical response values of each component under various load cases are extracted based on the static analysis of finite element model considering the plate rigidity of space frame system. The worst case combinations and types of mechanical response values under various load cases are obtained by MATLAB programming. The maximum resultant moment, maximum resultant shear stress and maximum axial force of strength checking effect are achieved to determine the worst stress position of component in the range of frame bent with the same dimension components.