Based on conventional meteorological observation data, Doppler radar data and FNL reanalysis data, a hailstorm process in winter on January 4, 2022 in Guizhou province was analyzed. The results showed that the hailstorm process was produced by the combined action of upper trough, low vortex with shear line, low-level jet, surface thermal low pressure and surface convergence line. The energy front was established before hail shooting, and the frontal zone was strengthened during hail shooting. The wet layer configuration showed that the air was humid at 500 hPa, which was not an obvious upper-layer?dry?and?lower-layer wet .The height of 0℃ layer and -20℃ layer was 70 ~ 100 hPa lower than that of spring hail. Compared with the convective parameters of thunderstorm winds in spring and summer in Guizhou province,The convective Available Potential Energy (CAPE) value and the total precipitable water (PWAT) value of this process were lower than the thresholds of relevant parameters in spring and summer, While the values of downdraft convective available potential energy (DCAPE) ,the temperature difference between 700 hPa and 500 hPa (T75) and the Temperature dew point difference between 850 hPa and 500 hPa (Td85) were significantly higher than the thresholds of relevant parameters in spring and summer. The influence process of convective storms was divided into two stages. In the first stage, the echo intensity was strong and well organized, forming the bow echo complex (BEC) with the rear inflow notch (RIN), which was the main reason for the occurrence of thunderstorm winds.The continuous occurrence of three body scatter signature (TBSS), high hanging strong echo and wide weak echo region (WER) made the hail density in the first stage high and locally accompanied by large hail; In the second stage, the echo intensity was weak and the organization was poor, so only small hail was generated, and the hail density was sparse.