Abstract: In the context of global warming, the frequency, intensity, and duration of heat waves are increasing, which seriously threatens the population health and socioeconomic development.How to identify the frequency belts of heat waves and clarify the potential population exposure risk of heat waves has been becoming a hot topic of academic concern.According to meteorological station data and demographic data, we used heat wave index to measure the severity of heat waves, and combined the heat wave days defined by wet bulb global temperature and population census data to construct the population exposure risk model of heat waveWe revealed the spatial-temporal evolution characteristics of heat waves and population exposure risk at the county scale in the Yangtze River economic Belt from 1964 to 2021.The results showed that: (1)The cumulative heat wave index in the Yangtze River Economic Belt showed a trend of first decreasing and then significantly increasing, with a spatially decreasing feature from the southeast to the northwest, and has an obvious spatial agglomeration.(2)In the past 60 years, the population exposure risk of heat waves in the Yangtze River Economic Belt increased by 962%, and the spatial distribution pattern was "one low and three high", which implied that the western region was low, while the Chengdu-Chongqing urban agglomeration, core areas in the middle and lower reaches of the Yangtze River Economic Belt were high.The agglomeration mode of population exposure risk of heat waves mainly presented an overall agglomeration, with local spatial agglomeration characteristics consisting of high exposure risk districts and counties and low exposure risk districts and counties.(3)Population factors and climate factors played a key role in changes in population high temperature exposure riskAfter 2000, the role of climate factors gradually strengthened, with the contribution rate increasing from about 50% to about 80%From a regional scale, population factors and climate factors contributed the most to the change of population exposure risk of heat waves in the middle and lower reaches.