The marine structure of 2×50，000 DWT wharf in Luoyuanwan Bay adopts a high piled structure with frontal sheet piles，which is a kind of complicate hybrid structure. In order to guarantee the structure’s reliability，space member system and plane strain finite element model is applied for the computing the deformation of the frontal sheet pile. The key parameter values of the two calculation methods and the calculation results of the frontal sheet pile deformation are introduced，and the calculation results are compared with the actual deformation data，which verifies the rationality of the key parameters of the two calculation methods.