Abstract: An integrated optimization design system for turbine tenon/mortise has been set up.In this system,contact clearance was used for parametric modeling of turbine tenon/mortise.Nonlinear contact method was used for analysis of finite element by the strong commercial software of ANSYS which could get objective and other stresses by secondary development of language.Meanwhile,multi-island genetic algorithm and sequential quadratic programming were used for optimization in specified space.As a result,the maximal first principal stress and von mises stress decreased obviously under the condition of meeting the geometry and strength requirements.The system exhibits higher stability,feasibility and efficiency for engineering applications.