Abstract: The analysis model of tapered box-beam blade with the stability of flapping and lagging was built based on the finite element method(FEM).The sensitivity analysis method was provided under the condition of multiple constraints and objectives.The optimization was realized by using the non-dominated sorting genetic algorithm(NSGA-Ⅱ).Finally,the optimization result was compared with the designed model.The results show that the optimum solution results in a 1.147 times increase of the autorotational inertia,a 5.74%～8.6% reduction of the total rotor blade mass and a reduction in the peak-to-peak blade stress of 29.6%～30.1%,under the constrained conditions of blade rotating frequencies,autorotational inertia and aeroelastic stability.