Abstract: Based on conventional observation data and satellite data, a heavy rainstorm and severe convective weather process in Nanxi District of Yibin City from April 11 to 12, 2022 was preliminatively analyzed from the aspects of large-scale circulation situation, thermal and unstable conditions. The analysis shows the heavy rainfall and strong convection weather was a typical horizontal trough to vertical weather process caused by the strong northwest airflow behind the trough to guide the cold air to erupt southward under the cooperation of many favorable conditions such as low-level jet and low-level shear line. The unstable stratification of the upper dry and the lower wet and the unstable energy conveyed by the southwest air flow provided the necessary energy conditions for the occurrence of the strong convection. The evolution of satellite cloud images and radar echoes had a certain indication for the occurrence of the heavy rainfall and severe convection (especially for hail clouds).