The slope of a reservoir area is unstable and can be destroyed by natural disasters, such as strong earthquakes and rainstorms. Landslide bodies that enter the water and generate landslide surges pose serious safety risks to terminals, ships, and hydraulic structures in a reservoir area. After analyzing landslide data in a reservoir area, a series of comparative tests was carried out to investigate the propagation characteristics of landslide-induced tsunamis in channel reservoirs, and the changes in water level values at various monitoring points in the river channel after the landslides entered the water were explored. The effects of landslide width and thickness on the characteristics of landslide-induced tsunamis were analyzed. The main target was a fixed-velocity ship in landslide-swelling water. The complex nonlinear motion characteristics of the ship on the water were studied to determine the safe navigation range.