The heavy rainfall existed for a long time in the Jianghuai area in 2003 Meiyu period resulted in a flood. A heavy rain occurred in the Dual-Doppler coverage, up to 351.7mm rainfall in 24h from 20:00 on July 4 to 20:00 on July 5 in Chuzhou, Anhui Province. The three-dimensional wind of the heavy rain were retrieved by MUSCAT (multiple-Doppler synthesis and continuity adjustment technique) using the dual-Doppler radar volume scan data. It showed that the convergence line and the meso-cyclone at the low level play an important role in this heavy rain event. The vertical circulation is also clear in the event.