High-temperature extreme events are a major ecological and environmental problem faced by human beings. Focused on the risk assessments of such an extreme events, the research applied remote sensing, meteorological and socio-economic data from 2000 to 2020 with risk-exposure-vulnerability assessment framework to explore the spatial and temporal difference in the middle and lower reaches of the Yangtze River. Further, the spatial distribution of high-temperature risk has been obtained during three periods through analytic hierarchy process. The research results show that the high-risk areas are mainly concentrated in the provincial capital cities and around the Taihu Lake basin. Meanwhile, the high-risk presents an increasing trend, especially, the Taihu Lake basin shows the most obvious rising trend rate, as 7.33%.In addition, some higher-risk cities in the north tend to decrease, while the other in the south tend to increase, which show significant regional differences in the experiment area.