In this paper, the Moving Particle Semi-implicit (MPS) method and Finite Element Method (FEM) coupling computational method is applied to solve the problem of hydroelastic response of floating structures. The MPS method, a Lagrangian meshfree method, is suitable for simulating violent flows such as breaking waves on free surface. For a floating structure like the ship hull and floating breakwater, the typical feature of motion is a large rigid-body motion plus a relatively small deformation. Therefore, a rigid-flexible coupling strategy based on MPS-FEM coupled method is developed. According to the choice of structural element, appropriate data transformation schemes are adopted on the fluid-structure interface. In this paper, the grouping exchange technique is developed, which is applied on the interface of particle model-beam element. The reliability of present method is verified through simulations of fluid-structure interaction (FSI) problems including water entry of the elastic wedge, water entry of the marine panel and dam-break wave impacting on a mooring flexible platform, the obtained numerical result is in good agreement with the published data. Afterwards, the coupling of fluid and structure solver is also tested by various problems including the cases of three-dimensional deformable floating platform/ship slamming in waves.