Based on the Earth System Model, greenhouse gas emissions and atmospheric composition of CMIP6 and population data, the correlation between the change of regional mean temperature and extreme climatic indices was studied. Three climatic indices over East Asia under nine SSPs-RCPs scenarios were predicted, and the variation and attribution of population exposure to high temperature were analyzed. The results indicate that 1) there is a robust correlation between the change of global mean temperature and regional extreme climatic indices, which can be used to predict the latter in the future. 2) East Asia will experience increasing risk of extreme climate event in the future decades under SSP2-4.5, SSP4-6.0, SSP3-LowNTCF, SSP3-7.0-Baseline and SSP5-8.5-Baseline scenarios. But taking mitigation measures in advance could reduce such risk significantly. 3) Future population exposure to high temperature of three typical regions of East Asia, which is affected by both climate and population factors, changes dynamically over time and regions. Under most scenarios, the effects of climate and population factors are gradually weakening and strengthening, respectively. The population exposure to high temperature of Southern China is significantly higher than that of Southwest and Central China, and the relative contribution of climate factors is also higher than that of these two regions.