Abstract: On January 11, 2013,a super catastrophic landslide took place in Zhaojiagou village of Zhenxiong County, Yunnan Province, and made 46 people died and serious economic losses. Based on multiple in-situ investigations and geologic survey, the landslide features and its failure mechanism are studied in the paper. The landslide took place in a natural accumulation slope mainly composed of colluviums and diluvium, and the slope structure has the characteristics of increasing in clay content and denseness but decreasing in porosity and permeability from slope crown to its foot. The main scarp developed along the steep interface of the accumulations and the strongly weathered sandstone bedrock, while the sliding belt developed along the soft layer of diluvium. Before the landslide there already existed a remarkable tension crack in current main scarp and a compression failure in the slope front, which typically is the failure mechanism of Creep-Crack. The main landslide body moved first and the 3 small landslides followed in its left and right flanks as well as the back slopes, and the landslide debris moved in belts. The natural water content of the sliding belt is very close to its liquid limit, and its plastic index is more than 10,which means that the soil is in the liquefied-plastic state and with low shear strength. The high speed at the moment of departure is the result of the long-term accumulation of strain energy but instantly releasing, the high speed during movement is related with the liquefaction of the landslide debris and the bed soil, and there exists proofs of debris flying. It is suggested to strengthen the deformation monitoring of adjacent slopes and the geohazard forecasting of similar accumulation slopes in Wumengshan region.