To alleviate the contradiction between the efficiency and accuracy of the composite material in the fluid-structure interaction (FSI) simulation, an equivalent method of the composite material is proposed based on the constitutive homogenization theory, and the iterative algorithm of FSI is explained. The open-source tool preCICE is used to verify the accuracy and efficiency of this method in terms of FSI analysis under both constant and time-varying fluid boundary conditions. The results show that the error of the equivalent method is within a reasonable range compared with the direct layered simulation, and even if the benefits of reducing the number of solid elements brought by the equivalent method are ignored, the calculation efficiency is still significantly improved; the relative error of simulation results under constant fluid boundary conditions is less than 5%, and the coupling iteration efficiency is increased by 20%; the relative error of the coupling scenario under time-varying fluid boundary is less than 10%, and the coupling iteration efficiency is increased by 40%.