In order to improve the modeling efficiency and realize the deformation simulation of helix twisting structure, a computer-aided design system based on mass-spring model is developed. The geometry structure of helix twisting structure is presented and massspring model is applied in the deformation simulation. Moreover, the key technologies such as coordinate mapping, system render and system architecture are elaborated. Finally, a prototype system is developed with Visual C++ and OpenGL, and the proposed system is proved efficient through a comparison experiment.