Abstract: In large deformation problems, the FEM will encounter mesh distortion and severe time step reduction. On the contrary, the material point method (MPM) does not suffer these difficulties. However, the accuracy and efficiency of the MPM are lower than the FEM in small deformation problems. Recently, a coupled finite element material point method (CFEMP) was proposed by our group to fully take advantages of both the FEM and MPM. In the CFEMP, the FEM and MPM are used to simulate the small and large deformation bodies, respectively. The interaction between two bodies is realized by the contact algorithm. Thus, the high accuracy and efficiency of the FEM is retained, while mesh distortion and severe time step reduction are avoided. The CFEMP is very suitable for the fluid-structure interaction problem, because the structure deforms little but the fluid deforms severely. In this article, the CFEMP is first reviewed briefly and then applied to the fluid-structure interaction problem. The results show that the CFEMP is a powerful tool for modeling fluid-structure interaction problems.