In view of the complex problems of the structure and stress of the lower lock head of Dongfei River,the displacement and stress field under different working conditions are analyzed by 3-d nonlinear finite element ABAQUS software.Calculation results show that using three dimensional finite element analysis software for complex structure has more advantages than in the past the traditional two-dimensional graphic calculation analysis method,the horizontal displacement and vertical displacement of lower lock head of Dongfei River can satisfy the requirements of specification.The results of three-dimensional finite element analysis can be more intuitive and accurate to reflect the overall strength and displacement of the lower lock head,which can provide a basis for evaluating the security state of the structure.