In this paper, we conduct a numerical simulation analysis of the catastrophic 2009 Jiweishan landslide in Wulong, Chongqing, China, which was characterized by its rapid velocity and long runout. The study is based on detailed geological field survey data and employed DANW runout analysis software to simulate the debris-flow process and accumulation characteristics of the landslide. The best match to the actual characteristics of the debris-flow process was obtained by applying the friction rheological model in the source and accumulation areas, and the Voellmy model in the scraping area. The simulation estimated the duration of the landslide to be approximately 101 seconds, with a maximum velocity of 39.2 m/s. The initial source volume, total accumulation volume, and runout distance obtained from the DANW numerical simulation results were in good agreement with the corresponding characteristics of the actual event. The modeling scheme and parameters employed here are expected to help clarify the motion of the Jiweishan landslide and improve the accuracy of future hazard assessments in areas with similar geological, topographical, and climatic features.