Specification algorithm applied in calculating the lock head does not consider the impact of nonlinear foundation material and 3-D structure’s integrity to the structural calculation of the lock head,so it can’t simulate the real stress and deformation of the whole lock head and foundation,thus affect the structural design of lock heads.To counter the above problems,we establish a 3-D finite element model of the lock head-foundation by taking a large ship’s lock heads for example.Considering the foundation’s material nonlinearity，the foundation material model uses the Duncan-Chang’s E-B model.The large scale finite element analysis software ABAQUS is used to analyze the stress distribution and deformation characteristics under working conditions of the lock head.The results show that the canonical algorithm is generally conservative,but it is unsafe at the side pier’s cross-section near the gate and the edge of the pier and the bottom.