A new method was proposed to improve the calculation of the composite rotor’s torsion stiffness.First

the flow of the blade’s structure design and analysis were studied.Then

all the material and geometry profile information of the blade construction were obtained by expanding the methods of blade parametric module definition and blade geometric modeling.Finally

the efficient calculation equations for cross-section torsion stiffness of composite rotor blade were derived based on the thin-box beam theory.One of the advantages of the proposed method lies in that the precision loss of model simplification is eliminate by taking the blade’s refined geometric model.On the other side

by importing the ply block

equivalent thickness and slenderness radio conception

and due to the analytical form of the calculation and the automatic geometric extraction

this method is quite suitable for practical use.Experimental results demonstrate that the method can complete the blade structure design and analysis efficiently.