Flash drought events occur frequently in Southwestern China, and a notable upward trend is predicted for the future. Attention should be given to how the severity of flash droughts and vegetation vulnerability hinder vegetation from recovering to their original state, leading to losses. Vegetation resilience and vulnerability to flash droughts was assessed in dry years by adopting a 'resistance-resilience' framework from a new perspective, and we measured the significance of various drought characteristics in affecting vegetation reduction by using the boosted regression tree (BRT) model. The results showed that croplands in the Sichuan Basin displayed low resistance to flash droughts, whereas grasslands and forests in mountainous areas had high resistance. Croplands in the Sichuan Basin demonstrated high vegetation resilience, while Guizhou province showed low vegetation resilience. Most regions experienced high vegetation vulnerability to flash droughts, especially in the Sichuan Basin and Yunnan province. We found that croplands and forests in 2006 exhibited a significant decrease in LAI during flash drought events. Croplands experienced a significant decrease in LAI in regions where the drought duration (DD) exceeded 60 days, and the drought interval (DIV) ranged from 30 to 40 days. Forest regions with a DD exceeding 60 days and a DIV below 20 days experienced a high reduction in LAI. Furthermore, croplands and shrubs could recover once their vulnerability fell below thresholds of 0.34 and 0.30, respectively. The impact of species richness on vegetation resilience can be explored in future research. This study reveals the spatial patterns of vegetation vulnerability and provides information on preventing and managing vegetation deterioration in Southwestern China.