Abstract: In this paper, by using doppler weather radar, ground data observed by automatic station high space-time resolution and NCEP1 x 1 ° reanalysis data, on July 28, 2017 in Nanchong city of local strong convective weather caused by pulse storm background, environmental conditions, characteristics of radar observations and wind formation are studied and discussed.Resultsshow that: This severe convection event under the control of the western Pacific subtropical high, have unusually strong convective instability energy and sufficient ambient moisture, which provides very good conditions for the development of the convective storm. Boundary layer shear line and weak cold air flowing into the basin in the northeast and temperature gradient caused by uneven heating are triggering new storm. In the environment of weak vertical wind shear, thunderstorms in the process are characterized by pulsed storms. There are several pulse storms in this process and two main pulse storms causing strong wind in Nanchong city. After the strong temperature gradient triggered, storm monomer no.1 develops rapidly upward and downward. When it is mature and collapses, a downburst occurs, causing high wind at Gaoping station. A strong downdraft reaches the surface to form a cold center, The center of the cold and the warm core ahead form a strong temperature gradient called the cold pool density flow.The density flows create a strong pressure gradient, which overlays onto the divergent airflow in the lower layer, causing the extreme wind in the town of huafeng.