Abstract: A numerical model which translated the mass of the blade into the surface area of the wind turbine blade is presented. The reason is that it is hard to calculate the blade mass based on traditional composite laminated plate theory because of the complex shape for the composite wind turbine blades. Secondly, based on the amendatory wind turbine aerodynamic theory, the airfoils along the spanwise distribution is designed using the newly CQUA airfoil series within the region of whole generated power for the wind turbine. It is verified that the CQU airfoil series exhibit good aerodynamic performance. The multiobjective optimization model which maximizes the power coefficient and minimizes the blade area is proposed for the pitch regulation wind turbine. A mathematical model of design and optimization for a new 2MW wind turbine blade is established. Lastly, the wind turbine blade is designed by using an improved multiobjective particle swarm optimization algorithm. The optimization results show that, compared with the original 2MW wind turbine blade, the performance of the newly designed blade have been improved, and the area is significantly reduced which means that the mass is reduced greatly and also the material cost of the blade. Moreover, the load for the blade root is effectively controlled. The study of the new designed blade provides a theoretical basis for the designing of high performance, light quality and lowcost wind turbine blade.