Abstract: This paper aims to reveal the mechanisms and discrepancy in hail generation caused by multi - cell storms , and the focus is on the impact of mountainous terrain on hail formation and development. Based on the ECMWF ERA5 reanalysis data , MICAPS data , and radar data from Rongjiang County , detailed comparative analysis is conducted on the causes and structural characteristics of two severe hail events triggered by multi - cell storms in Majiang County , Guizhou Province , on April 16 and 29 , 2024 . The results show that : 1) The April 16 event was a prefrontal hail type , while the April 29 event was an elevated thunderstorm type . 2) Radar features indicate that in both processes , strong echoes ≥55 dBz exceeded 10 km , penetrating the air above the - 20℃ layer , accompanied by overhang structures and fall . 3) Both processes had moderate vertical wind shear and unstable energy , but differed in vertical moisture distribution . On April 16 , zone with relative humidity ≥80% were located between 1 . 0 - 2 . 5 km below 700 hPa , whereas on April 29 , such zones extended nearly to the 0 ℃ layer , representing the primary cause of differing hail sizes . 4) The west - high and east - low terrain of Majiang County significantly enhanced uplift. When storms with core echo intensity ≥50 dBz moved into the high - elevation western regions , they developed rapidly , making central and western towns more vulnerable . In general , this study elucidates the synergistic effects of terrain uplift and moisture stratification in mountainous hail processes in Majiang County , and could providing important insights for severe convective weather forecasting and warning in complex terrain .