Abstract: Based on the surface observations collected at various automatic meteorological stations,radar observations from CINRAD/CD Doppler weather radars,hail information obtained from field surveys,and the NCEP/NCAR reanalysis,we analyzed the formation mechanism of three-body scattering,the three-dimensional structure and development characteristics of storm cell of a rare and severe hailstorm in July 2020 in Tuoketuo County,Hohhot.The results show that:（1）The three-body scattering results easily from C-band weather radar rather than S-band weather radar;（2）The threebody scattering phenomenon is closely related to the strong echo of 55 or 60 dBZ,especially when the strong echo of 60 d BZ appears,the three-body scattering phenomenon also appears;（3）From the perspective of three-body scattering and volume of hail-cloud changes,volume of hailstorm clouds in60 dBZ shows three-body scattering even if it is less than 50 km~3;（4）The multiple three-body scattering is discovered,which is characterized by longer length that is three to five times height from the ground to strong echo of three-body scattering in the radial direction of the radar,scattering weakens gradually with the increase of multiple scattering times,therefore,intensity of multiple three-body scattering weakens gradually in the radial direction of the radar;（5）After the three-body scattering phenomenon appears for the first time,hail begins to appear,and the descending airflow makes the echo top height of hail cloud fall rapidly,and the 60 dBZ echo top height falls most obviously,and the vertical thickness decreases most seriously.After the hail falls,the echo bottom height at 60 dBZ increases rapidly and the volume decreases sharply.After that,the echo top height and volume of the storm cloud enters a stable stage.