Abstract: In order to quickly forecast the hydrodynamic performance of the composite propeller and conduct in-depth research on the fluid-structure coupling characteristics of the composite propeller, this paper combines the boundary element method (BEM) and the finite element method (FEM) to establish a fluid-structure coupling calculation method for the composite propeller, calculates the surface pressure and hydrodynamic force of the composite propeller blade by the boundary element method, transfers the calculated surface pressure of the blade to the finite element structural model, and transfers the deformation to the propeller by the finite element method. The surface pressure of the propeller blade is transferred to the finite element structure model, and the displacement and stress distribution of the propeller blade under the load are considered by the finite element method, and the deformation is transferred to the hydrodynamic calculation of the propeller by the boundary element method. The method was applied to calculate the 5471 propeller and compared with the experimental values in the literature to verify the feasibility of the method. Later, a comparative analysis of the hydrodynamic performance of the 5471 propeller type composite paddle and the rigid paddle was carried out. The study shows that the method realizes the integration of the hydrodynamic performance analysis of the composite propeller, which has the advantages of simple implementation, high calculation efficiency and accuracy, and can provide reliable data support for the adaptive design work of the composite propeller and improve the design efficiency of the composite propeller.