Abstract: According to the natural disaster system theory and disaster risk assessment principles, this paper aims to assess the risk of rainstorm flood and its secondary disasters during flood season in Qinghai Province under the background of global warming by identifying the risk factors of rainstorm flood disaster and vulnerability of disaster environment, based on the daily precipitation and temperature data derived from the 50 meteorological stations in Qinghai from May to October during 1961-2017 and basic geographic information and historical disaster data. The results showed that: (1) the temperature, precipitation, (heavy) rainfall days, and extreme climate events had increased since 1961 in Qinghai province; (2) Floods and the secondary disasters such as landslides and debris flows caused by continuous or short-term heavy rainfall increased, and the peak of rainstorm flood and secondary disasters came up from July to August in Qinghai province which accounted for 77.9% of the total disasters in flood season; (3) the rainstorm flood and secondary disasters occurred most frequently and serious in Guide, Xinghai, Guinan, Gonghe, Tongde and Hualong. This study is of great significance to the early warning of rainstorm flood and the timely formulation and implementation of the measures for disasters prevention and reduction, providing decision-making information for the work of meteorological disaster prevention and reduction.