Abstract: Frequent and severe drought events have posed the serious threat to vegetation growth and ecosystem stability. The underlying dynamics of vegetation response to droughts can be expected to predict and mitigate the impacts of these environmental stresses on ecosystems. However, a single ecological index cannot fully meet the requirements of the vegetation responses to droughts. In this study, a robust conditional probability model was constructed to combine the normalized difference vegetation index (NDVI), gross primary productivity (GPP), and the standardized precipitation and evapotranspiration index (SPEI). The Copula framework was designed to clarify the relationships between meteorological drought stress and the probabilities of vegetation productivity and canopy structure loss. Additionally, a systematic investigation was also made to explore the interactions between different vegetation growth statuses and environmental factors, as well as the driving forces behind drought trigger thresholds using partial least squares path modeling (PLS-PM). A case study was also carried out in the Yangtze River Basin (YRB) from 1982 to 2018. The temporal and spatial disparities were observed in the vegetation productivity and canopy structure response to the meteorological droughts. The results indicate that: 1) The proportion of areas where vegetation productivity and canopy structure in the YRB are positively correlated with SPEI is 50.61% and 63.04%, respectively.. Notably, the canopy structure exhibited a closer association with the SPEI, compared with the vegetation productivity. There was a shorter response time to the meteorological drought stress. The canopy structure shared the higher vulnerability under drought duress, compared with the vegetation productivity. 2) Spatially, the high vulnerability was found in regions, such as the Hanjiang Basin and the middle and lower reaches of the Yangtze River, in terms of vegetation productivity. While the increasing susceptibility of canopy structure was displayed in the Jinsha River Basin and the mainstream of the Yangtze River. 3) The average probabilities of loss were 20.04%, 23.63%, and 28.99%, respectively, for vegetation productivity under mild, moderate, and severe drought stress. The heightened vulnerability was predominantly concentrated in the Hanjiang Basin and the middle and lower reaches of the Yangtze River. Canopy structures shared the average probabilities of loss of 23.26%, 24.77%, and 26.86% under similar drought stress levels. Among them, the regions of elevated vulnerability were located primarily in the Jinsha River Basin. 4) There were starkly pronounced disparities of vulnerability among various vegetation types over the basin. Irrigated cropland and evergreen broadleaf forests showed higher-than-average probabilities of productivity loss (21.05% and 17.26%, respectively). While the grasslands and evergreen needleleaf forests demonstrated elevated probabilities of canopy structure loss (36.35% and 35.73%, respectively). Furthermore, the wetter regions exhibited higher average probabilities of vegetation productivity loss under varying intensities of drought stress. While the drier regions showed the heightened average probabilities of canopy structure loss. 5) Canopy structure was more susceptible to external disturbances. While the vegetation productivity was dominated by the soil moisture and its own canopy structure. There was a complex interplay between vegetation responses to drought and environmental factors in the YRB. The findings can provide invaluable insights for the effective management and conservation of ecosystems against droughts.