Abstract: The motion of submarine landslide might generate tsunami, destroy the offshore facilities and threatening the safety of coastal zone. At present, the research on submarine landslide generated tsunami is in the ascendant. Mih granular flow model is adopted to control the movement of sandy landslide with low cohesive. Two-phase model is used to calculate the interaction of soil/water. RNG model is applied to control the dynamic of water. Based on granular flow model, the coupling numerical analysis method of submarine landslide tsunami is established. This full coupling model can be more accurate to characterize the movement of slide, the interaction between the sliding mass and the water, and the following impulse wave process of generation, propagation, and run-up. The case of simple submarine landslide in water tank is used to study the whole process of submarine landslide and the following tsunami. Numerical analysis presents the inhomogeneous dynamic of deformable slide mass, the differentiation flow of density, the hydroplaning mechanism, the impulse wave characterized by trough, and such typical phenomena of submarine landslide and tsunami are generated. These mean the numerical model built is valid. Low and non-cohesive submarine landslide exist in many sea regions (including north of the South Sea, China). Therefore, this numerical method is worth spreading and making further research and improvement.

Key words: granular flow equation, coupling model, deformable submarine sliding mass, tsunami, hydroplaning mechanism