Abstract: In marine seismic exploration, seawater and submarine strata constitute a typical fluid-solid coupling medium. Seismic wave propagation is accompanied by complex reflection, transmission, and wave-mode conversion. Traditional macroscopic numerical methods have certain limitations in interface processing and wavefield fidelity, resulting in numerical errors and numerical dispersion. Based on mesoscopic kinetic theory, we developed a lattice Boltzmann-lattice spring (LBM-LSM) coupled method for seismic wavefield modeling in marine fluid-solid coupling models. The method adopts a unified grid and space-time synchronization mechanism, and realizes two-way fluid-solid coupling through interface momentum exchange, strictly satisfying the dynamic continuity condition at the interface. Numerical tests were carried out on two-layer and four-layer marine geological models and verified by comparison with the finite difference method (FDM). Results show that the proposed method well agreed with the traditional method in wavefield morphology and propagation travel time, with higher modeling accuracy, and can effectively suppress numerical dispersion and dissipation, leading to better wavefield fidelity. The method adopts unified grid iteration and is convenient for parallel expansion. In addition, it clearly characterized the direct waves, reflected waves, and transmitted waves, and accurately identify various wave types. Therefore, this method can characterize seismic wave propagation more realistically in mesoscopic scale, providing a new high-precision tool for marine seismic forward modeling, stratigraphic identification, and marine geo-engineering assessment.