Abstract: The ERA-interim final-analysis data, precipitation data of national automatic stations are used to analyze the characteristics and causes of a continuous server rainstorm in Sichuan Basin from August 10 to 14, 2020. The results show that the precipitation process was divided into four stages, and the precipitation zone moved from southwest to northeast of the basin. The effective coordination of synoptic scale system provided favorable circulation background, with the cooperation of cold air and the warm moist flow, the continuous severe rainstorm occurred. At the time of heavy precipitation in each rainstorm area, the strong convergence of positive vorticity and negative divergence in the lower layer and the strong divergence of negative vorticity and positive divergence in the upper layer were conducive to the upward movement of the atmosphere, providing dynamic conditions for the continuous server rainstorm. Compared with the second and third stages, the vorticity, divergence and vertical velocity in the first and fourth stages were obviously smaller, which made the less accumulated precipitation. The rain storm center, the water vapor convergence center and ascending region in each stage were all located in the southeast of the low-value system in the middle and low level. In the second stage, the strong water vapor convergence and the consistent and strong upward movement of the atmosphere uplifted and transported the water vapor to the middle and upper troposphere. Therefore, the accumulated precipitation in the second stage was the largest.