Abstract: Using Doppler radar data,Give the detailed analysis to the strong hail bow echo which occurred in Qiandongnan state on May 8,2015.Results show that the reflectivity factor to maintain strengther and longer is the obvious characteristics of the hail process,echo intensity gradient is larger in the front of squall line echo band and bow structure is maintained for a long time. At radial velocity,the changes to the difference at the positive and negative velocity on both sides of zero velocity line,zero velocity line rotation and wind region reversing are the most common characteristics of strong convection weather process. At RCS,the typical weak echo region,strong echo overhanging and stretching height of strong echoes exceeding above -20℃ level. At RCS,inclined upward airflow and middle level sinking air formation the radial convergence zone. There are a good corresponding relation between the hail and the jump of vertical liquid water content,hailing time,the VIL value to maintain the value of the larger.