To investigate the far-field propagation characteristics of three-dimensional impulse waves generated by subaerial landslide, a three-dimensional landslide-generated wave model was established using FLOW-3D. The process of the landslide mass impact with water splash followed by landslide-induced wave generation and propagation were investigated under the condition of slides with different thickness, width and variable entry speeds. The results show that the landslide wave propagation keeps stable beyond a distance of 7 times of water-depth from the slide entry point. The dimensionless wave height and wave period are determined by the Froude number of landslide mass, the dimensionless motion time and the landslide body size. The energy conservation rate from the landslide to the far-field wave fluctuates from 8.0% to 19.7%.