Longitudinal and transversal crossbeams play a significant role in connecting towers and making united action of overall structure in Three Gorges Project vertical ship lift. A reinforcement design for these beams is an important step in the design of civil structure of the towers. With 3D FEM, a static analysis of the ship lift towers is performed by using solid elements. Internal forces of beam structures are calculated directly from nodal forces of solid finite element method, by which its calculating precision is higher one order than the conventional stress integral method and the design may avoid errors due to corner singularity of stresses. Based on secondary development of MARC, a simple way is found to implement numerical solutions with simple programming and easy operation, in stead of writing a FEM program. At the same time, in order to reduce amount of work when treating a number of beams under complicated load cases, an automatic programming operation is proposed for data preparation, internal force (including tensile force) calculation and stress results show.