Based on the Blade Element Momentum theory, the model of load and aerodynamic characteristics for wind turbine blades is carried out that the blade tip loss is fully considered. Applying the structural dynamic equations of blades, the aeroelastic model of the rotating rotor and the numerical simulation method of the deflections are presented under the aerodynamic loads and centrifugal forces. Coupling the aerodynamic characteristics and the structure stress, the flapwise and edgewise loads, deflections and accelerations of the rotating blades are calculated and plotted. Finally, one 5MW wind turbine rotor is chosen that the aerodynamic loads and output power are simulated. The bending displacement and vibration response are investigated and compared between different wind speed and working time to prove the accuracy and reliability of the model presented in this paper. The results have important theoretical significance for the fatigue life prediction and vibration noise estimate of wind turbine blades.