Abstract: Based on the daily temperature and rainfall data of 104 meteorological stations in the Sichuan basin from 1981 to 2022 and the daily reanalysis data of European Centre for Medium-Range Weather Forecasts (ERA5), the characteristics and causes of the regional extreme high temperature process in Sichuan Basin in 2022 were analyzed. The analysis results show that 87% of the stations in the regional extreme high temperature process in August 2022 have the highest temperature breaking through the historical extreme value, and the highest temperature in this station is 1.4℃ higher than the historical extreme value on average. The duration of regional extreme high temperature process is up to 35 days, which is the longest in history, and the area of influence is also the largest, nearly twice the historical average. At the same time, the comprehensive strength evaluation level of the process is particularly strong, with an index of 37.49, ranking first. and the second strongest process in history (2016) was only 12. The intensity of the South Asia High pressure that caused this regional extreme high temperature process is 14 dagpm stronger than that of the same period in history, and the ridge point is 20 longitudes to the east. The West Pacific subtropical high was 9 dagpm stronger than that of the same period of history, and its ridge point was 50 longitudes to the west. The middle and upper tropospheric layers above the basin were controlled by strong high pressure, resulting in the continuous prevalence of downdraft in Sichuan basin, with obvious warming. The no adiabatic factors play a key role in the high temperature weather under the control of the Western Pacific subtropical high, The ground net radiation value is 3.5×10⁶ J/m² higher than the annual average, the strong ground net radiation increases, making the temperature rise.