Abstract: Based on the conventional observation data of national station and regional station in Aba Prefecture, the 6-hour reanalysis data of ERA5 and the new generation weather radar data of Aba, the process of a wide range weak precipitation and thunderstorm gale on the afternoon of April 27, 2023 was analyzed, and its circulation characteristics, environmental conditions and radar characteristics were found out. The conclusion is drawn: The process was strong in intensity, wide in scope and weak in precipitation. The obvious synoptic scale system triggering, effective energy accumulation and extremely favorable environmental conditions caused the large-scale thunderstorm and gale weather. Poor humidity conditions were the main reasons for the weak precipitation. This large-scale thunderstorm gale was caused by the development of banded convection into bow echo moving eastward and southward. The strong wind in Hongyuan had obvious features such as low elevation and large wind velocity area, rapid decline of reflectivity factor centroid, strong and deep mid-level radial convergence after the storm. The strong wind in Maerkang had obvious characteristics such as echo overhanging and low-level weak echo area, weak mesocyclone, deep middle-level radial convergence and so on. The availability of radar storm tracking products was good, and the availability of UAM products was not high.