Rockfalls in reservoirs are prone to induce surges,posing a severe threat to passing vessels and facilities.A scheme combined Single-phase free-surface method (SPF),momentum exchange method(MEM),and Lattice Boltzmann method (LBM) is proposed to predict the impact of rockfall-induced surges.First,the LBM-SPF model is used to simulate the motion of the free surface,and the MEM model is used to calculate the hydrodynamic force acting on rock mass.To address the incompatibility issue arising from the coupling of LBM-SPF model and MEM model,a correction scheme inside the solid is induced.The simulation results of the single particle and double particle sedimentation in cavity show the feasibility and accuracy of the method designed in this paper.Moreover,the validation experiments of Scott Russel\'s wave generator show that the proposed scheme can simulate wave profile stably.The simulation results emphasize that the waves induced by rockfalls have a significant impact on the safe operation of the Laxiwa dam and the passing vessels in the reservoir.