Abstract: Based on Chengdu Doppler Weather Radar and other conventional meteorological data, the supercell storm occurred on 27 July 2015 in the middle of Sichuan is analyzed. The result show that: (1) The value of CAPE is significantly increased and the appropriate height of 0℃ layer and-20℃ layer, which provided instability energy for storm and hail. (2) There are many supercell features of Doppler radar echo, such as hook echo, weak echo region, vault, meso-cyclone and etc. meso-cyclone appear in mid-level at first, then spread up and down. (3) It is also found that the abrupt increase of vertical integration of liquid water content (VIL) is ahead of hail, which has indicating significance on hail forecasting. (4) TBSS (three-body scattering spike) is another feature of hail forecasting, TBSS are found at 5 ~ 10 km, which only appear in two volume scan ahead of hail.