Abstract: Based on the precipitation data from April to October during 2013—2022, combined with conventional ground observation, upper-air observation and NCEP reanalysis data, the statistical analysis of the regional warm-sector rainstorm in Liangshan Prefecture were carried out, and 42 cases of regional warm-sector rainstorm were selected for statistical analysis and synoptic diagnosis. The results show that according to the weather situation and main influence systems, the regional warm-sector rainstorm in Liangshan Prefecture can be divided into five types: southwest vortex type, cold shear type, warm shear type, southwest wind type and southeast wind type. Among them, the southwest vortex type is the most, and the southeast wind type is the least. All kinds of regional warm-sector rainstorms have the characteristics of short-term heavy precipitation. The heavy precipitation occurs from evening to night, and the precipitation intensity decreases during the day. The southwest vortex type often appears in the center of the vortex or the southeast side of the periphery, the precipitation is concentrated, and the extreme heavy rainfall with hourly rainfall ≥50 mm is easy to appear. The cold shear type rainstorm often appears in the southeast of cold shear line, the warm shear type rainstorm often appears in the northeast of warm shear line. The southwest wind type rainstorm is concentrated and wide, mostly in the low-level consistent southwest airflow zone, which is particularly common in the wind speed convergence zone and the pulsation zone. The water vapor of the southeast wind type rainstorm mainly comes from the South China Sea and the tropical western Pacific Ocean, and the water vapor of the other four types mainly comes from the Bay of Bengal. The five types of warm-sector rainstorm all occur in unstable stratification with high energy and high humidity, with the strong vertical upward movement. The average physical quantities of southwest wind type, southwest vortex type and southeast wind type are better than those of cold shear type and warm shear type, and the overall configuration of physical quantities of southwest wind type is better.