Abstract: The Three-River-Source area is featured with the most serious snow disaster in Qinghai Province, which has a great impact on animal husbandry. Using the daily snow depth data from 1961 to 2020, the spatial and temporal distribution characteristics of winter snow disasters in the Three-River-Source area are analyzed. MOD10A1 data are also used to extract snow cover days. The minimum temperature, snow disaster intensity and snow cover days are selected as disaster causing factors, the elevation and slope direction are selected as disaster environmental factors, and the population, livestock and type of land use are selected as disaster bearing factors to build the snow disaster risk assessment model to assess the winter snow disaster risk in the Three-River-Source area. The results show that snow disasters in winter of the Three-River-Source area show an increasing trend, with Chengduo hit most seriously, and with the extremity obviously intensified after entering the 21st century. Chengduo and Maduo are the areas with the lowest winter temperature, the strongest snow disaster intensity and the largest number of snow cover days in the Three-River-Source area, leading to the highest risk of snow disaster causing factors. Moreover, the sensitivity of snow disaster environmental factors increases from east to west. The eastern region is home to relatively large population and livestock, while grassland is widely distributed in the central and eastern regions. So the vulnerability of disaster bearing factors in the Three-River-Source area is mainly medium. Based on the selected factors, the snow disaster risk assessment model is established to assess the winter snow disaster risk in the Three-River-Source area. Chengduo, Dari, Gande, Zeku and the west of Maqin are the areas with high snow disaster risk.