Abstract: Pattern search method is proposed to identify the operational bridge parameters indirectly according to the vehicle responses, which could be applied to the problem of multi-local-extremism and discontinuous data. A preliminary discussion was performed on the Generalized Pattern Search method through a simple numerical example, and the basic concepts of the pattern move, mesh size, poll were represented. The search process with different noise levels was discussed on the function value, iterations, mesh size and poll results. It is concluded that the method could be use to identify the bridge parameters according to the vehicle responses, even in high noise level. The problems of the local extremums and the convergence could be avoided partially.