Abstract: The characteristics of discontinuous fields under discontinuous stress boundary were analyzed.Based on the deduction of the upper and lower bound theorems,the mechanical model was established,and the efficient numerical method was presented.By solving three kinds of boundary-value problems,the stress fields and the related velocity fields were obtained.The weight of soil and the friction between soil and retaining walls were taken into account in this course.The stress fields were satisfied with the velocity boundary of retaining walls rotating around the base.The rigorous earth pressure contribution was obtained at the same time.It was shown by the computated results that the proposed approach could be used to solve the limit equilibrium problem.