Abstract: Fluid-structure interaction (FSI) is a significant area of research and a challenging topic in the field of structural engineering. FSI involves a range of crucial issues, including the behavior of free surfaces, the analysis of strong nonlinear structural responses, and the coupling at the fluid-structure interface. In this study, a novel computational method for fluid-structure interaction is proposed by combining the Finite Particle Method (FPM) and Smoothed Particle Hydrodynamics (SPH). Firstly, the FPM for the computation of structural model is presented, which includes the calculations of the motion equations of motion of particles and the internal forces within planar beam elements. Subsequently, the SPH method for the computation of fluid model is implemented, including the discrete formulation of the fluid governing equations, the control strategies for tension stability controlling, and the scheme for time integration. On these bases, an approach for the computation at FPM-SPH interfaces is put forward. Specifically, the arrangement of virtual particles at coupled interfaces is provided, and the algorithms for passing interface pressure and coordinating interface displacement are proposed. In these algorithms, the correspondence of physical quantities between structural particles and fluid particles at the interface is established. The computational framework of the method proposed is thusly constructed. Three examples, i.e., dam-break flows impacting an elastic beam, an elastic gate under water pressure, and water falling on a rectangular membrane structure, are modelled and analyzed using the method proposed. The numerical results of the fluid motion, of the structural deformation, and of the displacement time-histories are consistent with the experimental results or the results in the existing literatures, demonstrating the effectiveness of the method proposed.