Abstract: Rapid and long run-out landslides, one of the most serious geological hazards in China, caused great damage due to its sudden, violent, high speed and long run-out characteristics. Therefore, it is of great significance to study the catastrophic process for prevention and mitigation of the hazard. DAN-W is a dissipative particle dynamics based on Lagrangian finite-difference and inverse simulation of the detrital flow process. This paper studies the characteristics of the Banana-Tree Landslide in Ailao mountain area. DAN-W was used to establish the calculation model and analyze the catastrophe process. The slide path was divided into three segments:sliding source segment, scraper segment and accumulation segment, according to landslide zoning and scraping effect. The results showed that the maximum speed of frontal part was 26m/s, the frontal rear part was 30m/s at the shear exit; the maximum slip distance was 420m, sliding off shear outlet after 14s, and stopped after 30s. The results are consistent with the actual situation.