Based on the S-band dual polarization Doppler weather radar of Xuzhou and Nanjing, the single polarization radar of Suqian and Huaian, and the reanalysis data, the paper analyzes the circulation background, instability mechanismdynamic, uplift conditions, radar echo and the evolution characteristics of dual polarization radar parameters and the wind inversion technology of dual radar of a wide range hailstorm process accompanied by a thunderstorm and short-term excessive rainfall occurred in Jiangsu Xuzhou, Suqian, Huaian, Nanjing and Changzhou on July 6, 2019.The results show that a wide range of strong convective weather occurredwhen the cold vortex falling on high level and horizontal trough swing south, the trough line swept across Jiangsu from north to south before midnight on the 6th, the lower layer warm and humid air flow moved northward, under the background of strong unstable circulation on upper and lower layers, and the low pressure slowly moved eastward and the South pressure provided the convergence and uplift conditions.Generally, the intensity of radar echo is over 50 dBZ and the echo top is always above 10 km in this procedure.Additionally, it appears that there are significant Three Body Scattering Spikes, cyclonic convergence and storm top divergence.A hail storm can be identified by its polarization parameters (such as the Z_DR, CC, K_DP).Hail storm usually exist in the area with strong reflectivity、low value of Z_DR, and CC.The typical value of Z_DR is usually between -1.0 and 0.2 and the value of CC is less than 0.85.Additionally, Z_DR and K_DP columns help identify hail, thunderstorms, and short-term heavy rainfall.The characteristics of the two polarization parameters above can be used for the prediction of strong convection and hail recognition.As a result of study of the hail period using double radar wind inversion technology, a noticeable downdraft is found.In the three-dimensional flow field structure of the hailstorm supercell, the cyclonic air flow forms at the front of the storm, and then gradually inclines to the top of the storm to form the anticyclonic air flow, which forms the downdraft;in the weakening stage of the system, there is a strong downdraft, strong echo bottom and ground.Due to dual radar's ability to retrieve fine structure of three-dimensional wind, it is possible to deepen the understanding of hailstorm cloud structure and improve the prediction and early warning capability of severe convective weather, such as hailstorms.