The aerodynamic design of tiltrotor must be synthetically considered to meet the different requirements between helicopter mode and fixed-wing aircraft mode, a set of optimization design methods for aerodynamic shape of tiltrotor is established by multi-objective genetic algorithm based on Kriging surrogate model. In order to improve the efficiency, the Latin hypercube method is employed to generate the initial sample points, and the Kriging surrogate model is built to replace the numerical simulation of flow. The objective function of optimization is maximum hovering thrust and cruising efficiency, with constraints of non-increasing hovering power and non-decreasing cruising thrust. The results show that, the hovering efficiency of optimized rotor is 71.0%, and the cruising efficiency of optimized rotor is 63.1%. The optimized rotor is predicted by unsteady CFD (Computational Fluid Dynamics) simulations and validated by wind tunnel test which show the good agreement between two methods. Also, the result of optimized rotor meet the design requirements and it indicates the reasonability of optimization method and numerical simulation.