This paper explores the characteristics of the mesoand microscale systems in the southwest vortex during a rainstorm occurred in the Hanzhong basin from 28 to 29 June 2015 under the influence of the southwest vortex. For reference, the data of Doppler radar, NECP reanalysis, conventional observation and automatic meteorological stations are utilized. Under the 850 hPa the southwest vortex, the rainstorm formed by the combined effect of 700 hPa lowlevel jet stream and the upper divergence at the tropopause. The Foping and Zhenba, which locate at the northeast of the southwest vortex, were two mainly heavy rainfall areas. In the radar intensity field, the supercell kept developing in the northeast of southwest vortex for approximately 15 to 2 hours, which corresponds two heavy rainfall centers with the echo intensity reaching the highest (58 dBz), and in the velocity field, the supercells were accompanied by deep mesocyclones, which appeared at the southwest and central parts of the supercells. Besides there existed a banded adverse wind area over Zhengba. The results indicate that it was the supercell in a mesoscale 〖JP2〗convective complex in the southwest vortex, directly leading to the torrential rainfall (709 mm/h 〖JP〗and 321 mm/h) in Foping and Zhengba. The intensity change of the supercell determined the development of rainstorms in the Hanzhong basin. Meanwhile, we summarize the characteristics of the echoes with different magnitude, which provides a theoretical basis for rainstorm prediction.