Abstract: Using CMORPH fusion data, surface precipitation data and satellite cloud image data, the persistent rainstorm processes in Sichuan Province from June 22 to 24, 2015(Process 1) and July 10 to 12, 2018 (Process 2)are studied. The two processes are compared and analyzed from the aspects of power, heat, water vapor and cloud images. The results show that: The falling area and strength of the two processes are different. In Process 1,the main precipitation was generated from northeast to central Sichuan Basin. Within 48 h, the precipitation above rainstorm was monitored in 338 regional automatic stations, and the maximum rainfall reached 313.5 mm. In Process 2, heavy rainfall occurred in the northwest of Sichuan Basin. In 48 hours, the heavy rainfall and above was monitored in 942 regional automatic stations, and the maximum rainfall reached 481.7mm. The two processes were formed by the interaction of multi-scale influence system such as high-altitude troughs, typhoons, shear lines. The landing path of the typhoon has an obvious influence on the rainstorm area of the Sichuan Basin.When typhoon landed from Guangxi, the precipitation tended to the north, while when typhoon landed from the eastern coast, the precipitation tended to the west. The two processes were backward dip trough with obvious baroclinic characteristics.In Process 1, precipitation stimulated the formation of basin vortex, which made the precipitation continue,the whole precipitation process was under unstable stratification, and MCC generated, and the precipitation was more than 30mm in one hour. In Process 2, as the subtropical high recedes eastwarded and the trough moved eastward, the precipitation changed from early convective precipitation to stable precipitation. From the development and movement of potential vorticity, the high potential vorticity of the two processes coincides with the occurrence period of heavy precipitation, and the use of potential vorticity has important reference value for the indication of torrential rain in Sichuan Basin.