Abstract: A severe convective process dominated by hail and thunderstorm gale occurred in north-central part of Guizhou Province on May 15, 2021. The maximum thunderstorm gale wind speed reached 44.3 m/s, and the maximum hail diameter reached 40 mm. Based on the MICAPS routine meteorological data, ERA5 hourly reanalysis data of ECMWF and Doppler radar data of Guizhou Province, the weather system configuration, physical quantity fields and radar echo characteristics of this process were comprehensively diagnosed. The results show that: (1) The 500 hPa plateau trough shifted eastward, and the cold advection behind the trough pushed the low-level shear line southward, which triggered the strong convective weather with the surface cold front and convergence line activities. (2) Before and after the process, the central and northern parts of Guizhou Province were characterized by an “upper dry and lower wet”and“upper cold and lower warm”. The southwest jet stream in the middle and low levels brought sufficient water vapor. The K index, temperature difference between 850 hPa and 500 hPa indicated the strong atmospheric instability. Additionally, there was a moderately strong vertical wind shear, suitable 0 ℃ and −20 ℃ layer heights. Overall, this environment was favorable for the occurrence and development of hail and thunderstorm gales. (3) The radar echo characteristics showed that multiple thunderstorm cells were generated and developed near the ground convergence line in the afternoon. The shape of echoes changed from clumpy to arched, with high centroids and high extension heights, and the 50~60 dBZ echos were closed to the ground. The echo exhibited characteristics of bounded weak echo regions, echo overhangs, and V-shaped grooves in the forward and backward, causing heavy hail and extreme thunderstorm gale. During the night, thunderstorm cells split and then coalesced, resulting in weakened intensity, and becoming a mixed cloud cluster of stratiform and cumuliform clouds, causing thunderstorm gales and short-term heavy precipitation.