Considering the tip loss of normal and tangential forces，a new aerodynamic model of wind turbines is given. Based on the new series of dedicated high-performance wind turbine airfoil，the functional expressions of wind turbine blade chord and twist angle span-wise distribution are studied，and then a new common functional equation of the blade shape is presented. Considering the wind farmer wind speed distribution，air density and industrial requirements of the wind turbine blade，aiming at the maximizing annual energy generation in constant and variable speed operation condition respectively，assigning the coefficients of blade distribution functions as the variables，a 2.3 MW wind turbine blade shape optimization model is established. Two kinds of superior blade are also optimized. The efficiency and the annual electricity production of the new blades are much higher than traditional blades. Among the new blades，the maximum power coefficients of fixed speed blade and variable speed blade are 0.515 7 and 0.517 7 respectively.