Based on the GMO fluid-solid coupling model and the k-ε turbulence model, a three-dimensional numerical model was established to simulate the generation and propagation process of landslide-induced impulse waves, by using the VOF method to trace the free surface of the fluid on FLOW-3D platform. The numerical results are in good agreement with the existing measured data. The effects of fluid-solid interaction and the motion of the landslide body on wave generation and propagation were analyzed. The simulation results show that the first wave height and the propagation velocity of the impulse waves can be obviously increased by ignoring the effect of the water on the landslide. The fluid-solid interactions affect the features of impulse waves mainly during the phases of the landslide contacting the water surface to the complete immersion. Through adopting the fluid-solid coupling model in the phase of the landslide entering into the water, and then specifying the motion trajectory when the landslide is completely submerged, the obtained simulation results can also accurately capture the generation and propagation characteristics of the impulse waves.