AbstractBecause involving a large number of discrete particles interacting with water, simulating the fluid–solid coupling problem of landslide‐generated waves in a virtual environment is very difficult. This paper employs the DualSPHysics multiphase flow model to relatively easily simulate the dynamics of landslide‐generated waves in large scales. In addition, the simulation results are well visualized by the marching cubes algorithm. It is found that, when the factors of the landslide scale, the water length, and water depth are fixed, the initial maximum wave height decreases as the water width increases. After the water is squeezed by the falling slider, one‐way and two‐way propagations of the surge are generated under 2D and 3D conditions, respectively. In addition, under the true‐3D condition, although the initial swell generated is smaller than the 2D and quasi‐2D conditions, it will generate a large wave height during the climbing and undulation of the near shore. In the 2D condition, the surge generated is almost the largest. Therefore, when using the DualSPHysics multiphase flow model to predict the maximum wave height generated by landslide surges, a 2D simulation can be used to improve work efficiency.