Abstract: Two historical extreme rainstorm processes of Sichuan Province in August 2020 were selected, the heavy precipitation was divided in terms of magnitude and duration, and its spatio-temporal distribution characteristics and relationship with radar echoes and lightning were analyzed. The results show that the short-time heavy precipitation mainly occurs in the period of 22:00~03:00, and the stations of 30~<50 mm/h are the most, and the region is concentrated in the western part of the basin. With the increase of precipitation level, the corresponding lightning density increases, and the hourly mean echo, the strongest echo and the weakest echo all show a trend of enhancement. With the increase of precipitation duration, the average intensity of negative ground flash increases. There is a good correspondence between the number of heavy precipitation stations and the high value center of lightning frequency in the first process. In the second process, with the precipitation level increases, the corresponding root mean square error of the echo decreases, while the first process is the opposite.