Abstract: The variational asymptotic beam section analysis method (VABS) was used to calculate the sectional properties of composite blades bending in rotational plane. On the basis of the Euler-Bernoulli beam model, the influence of bending amplitude was analyzed on the dynamic characteristics of the blades. The unsteady blade element momentum theory inconsideration of dynamic flow and dynamic stall model was used to calculate the aerodynamic loads. The gas power at various wind speeds was calculated for forward and backward swept blades with same control strategy, and corresponding analysis was also carried out regarding the aeroelastic response in the extreme wind conditions. Results show that, the influence of bending effect is weak on the sectional properties and the first several orders of the natural frequency, while the influence on the torsional direction is significant. It is also shown that for the same control strategy, the backward swept blade leads to the reduction in the gas power, and the suppression of the load fluctuation encountering extreme gust.