Abstract: In this paper, the material point software(Anura 3D) is used to set up the contact algorithm and fluid-solid coupling. Based on the M-C strength criterion, the whole process of the true submarine landslide in the South Mediterranean is simulated and back-analyzed. The coefficient of friction is 0.052. The landslide starts at the foot of the slope and gradually develops to the interior to form a whole landslide body. The whole body of the landslide accelerates and slides along the slope. At the 15th second, the maximum speed is 14.52ms-1,after which the friction is due to friction. ResistanceSlide force, the landslide body begins to decelerate. At the 21st second, the landslide body slides into a gentle section(slope is 1.1),the sliding force is close to 0, and the speeds of different particles are different, so the diffusion occurs in the horizontal direction. In the 57s, the speed drops to 0 and the sliding stops, The final sliding distance is 420.3m. The concept of the comprehensive friction coefficient() of the contact surface of the submarine landslide was put forward, and the phenomenon of soil softening and hydroplaning caused by seawater mixing during the sliding process of the submarine landslide was characterized by , and applied to the submarine landslide movement.