1.Introduction Nowadays with the development of computer technology, suspension bridges are designed by making extensive use of the nonlinear finite element method.Based on the finite displacement theory and advanced computation technique, it is so far the most accurate and mature computational method for suspension bridge.However, this method normally leads to analysis with a large number of variables involved, difficult to verify and tend to obscure the influence of key parameters on the overall behavior of the bridge.Any parametric variance will cause readjustment of the computation model, and the status that any model describes usually needs experienced designers to repeat the process of try for many times.