The method of twisting the blade using a trailing-edge flap is presented in this paper.The dynamic model of the rotor blade with the trailing-edge flap is developed based on the modified Greensberg quasi-static aerodynamic theory.The effect of flap deflection on the torsion of the blade is investigated.Results show that the angles of torsion are equal to-3.8° and 3° when the flap deflection is 6° and-6°,respectively.The flap deflection has a powerful effect on the blade bending deformation in flapping direction.When the flap deflection is 6°,the tip flapping displacement is 0.16 R.It is decreased by 50.8% in comparison with that without any flap deflection.So it is feasible to twist the blade by using the trailing-edge flap.