Abstract: For insufficient of minimum potential energy method research, model of shear potential with static equilibrium equation of sliding body virtual displacement is proposed, which can solve shear strength on failure surface. Moreover, stability analysis method of multi layer slope is forwarded. Results of paper examples show that:shear potential energy of sliding mass can influence stability factor of slope, and it can obtain reasonable result; paper method is feasible and reasonable, which result from stability factor of proposed method is close to limit equilibrium method; analysis method of multi layer slope not only considers contribution of sliding surface length and normal force, but also it is simple and easy to be used by engineering.