The gross primary productivity (GPP) of vegetation is a vital component of carbon sinks within terrestrial ecosystems. Understanding the cumulative and lagged effects of drought on vegetation GPP, as well as elucidating the response mechanisms of vegetation, is crucial for the ecological security of the Yunnan Province. However, research on the spatial and temporal heterogeneity of vegetation GPP drought response mechanisms and their influencing factors remains limited. Utilizing data on vegetation GPP and the standardized precipitation evapotranspiration index from 2001 to 2023, this study employed time-series analysis and the maximum correlation coefficient method to examine the temporal and spatial characteristics of meteorological drought and vegetation GPP in Yunnan Province. This study quantified and explored the cumulative and lagged effects of drought on vegetation GPP, considering the influence of long-term wet and dry conditions and altitude. The findings indicated that: (1) Over the past 23 years, Yunnan Province has exhibited a generally non-significant drought trend. High drought incidence primarily occurred in the northwest, west, and east-central regions, particularly during spring and fall. The multi-year average vegetation GPP was 1600.2 g·C m-2, demonstrating a highly significant upward trend (6.8 g·C m-2 a-1, P < 0.001), with notable interannual fluctuations. (2) The response of vegetation GPP to drought exhibited pronounced spatial and temporal heterogeneity. The most significant responses occurred in fall and spring. Spatially, the dry and hot valley areas were the most susceptible to drought, displaying a strong and rapid response. (3) Vegetation GPP in 52.0% and 54.9% of the province"s areas was significantly influenced by the drought cumulative effect and lagged effect, respectively. The time scales of the cumulative effect were predominantly short- to medium-term (4-6 months) and long-term (10-12 months), with the lag time primarily long-term (10-12 months). Compared with shrubs and forests, farmland and grassland exhibited stronger responses to drought over shorter timescales. The differences in lag times among the vegetation types were minimal. (4) Long-term dry and wet conditions and altitude were significant factors affecting the cumulative and lagged effects of drought. The intensity of drought impacts decreased as the environment transitioned from dry to wet, and as elevation increased, the time scale of cumulative effects lengthened, and the lag time shortened. Altitude exerted a greater influence on the intensity of drought impacts than wet and dry conditions, whereas the time scale of cumulative effects and lag time were more significantly affected by wet and dry conditions. The results of this study provided a scientific basis for the development of drought risk mitigation and response management strategies.