As global climate change intensifies, the frequency of extreme weather events is increasing, posing a serious threat to the stability of vegetation. Many studies have utilized partial correlation analysis, autoregressive models, and similar methods to investigate vegetation's responsiveness to climate change, providing significant insights. However, they often focus on qualitative aspects, neglecting the cumulative and lagged effects of climate change on vegetation. Accordingly, this study quantitatively assessed vegetation sensitivity to climate change, incorporating cumulative and lagged effects, aiming to offer a theoretical basis for preventing regional vegetation degradation. Based on AVHRR NDVI3g and ERA5-Land data, an autoregressive model was applied in the study to calculates the sensitivity of vegetation to climate change, considering the cumulative and lagged effects of climate on vegetation. The study further explored the spatio-temporal variations in vegetation sensitivity across China. The results indicate that precipitation, solar radiation, and temperature have varying cumulative and lagged impacts on vegetation across different climatic zones. Vegetation in arid regions shows extended cumulative and lagged responses to solar radiation, whereas in humid regions, it is predominantly affected by precipitation, exhibiting lagged effects for up to three months. Grasslands and cultivated lands exhibited shorter lagged responses to changes in temperature and precipitation, while forests in the Northeast showed a short-lagged effect in response to temperature variations. In humid regions, abundant precipitation resulted in a prolonged lagged effect of up to three months, whereas in semi-arid regions, the lagged effect was reduced to one month due to lower precipitation levels. The cumulative and lagged effects of solar radiation on most vegetation in China last for 2 to 3 months. Forests in southern humid regions exhibited a three-month lagged effect in response to temperature, while grasslands in semi-arid regions showed only a one-month lagged response. In contrast, Northeast forests and cultivated lands in central China responded to temperature changes in the same month. Vegetation sensitivity was generally higher in humid regions, gradually increasing from semi-arid to humid zones. In arid areas, the arid zone displayed greater vegetation sensitivity than in the semi-arid zone. Approximately 92.60% of vegetation in China exhibited low sensitivity, with a sensitivity index of 0.25, indicating a certain resistance to external interference. However, 7.40% of the vegetation, primarily located in the humid region of Eastern China region and semi-humid area of Northeast China, exhibited extremely high sensitivity, with a sensitivity index of 0.4. Vegetation growth in these regions was highly susceptible to climate change and faced significant degradation risks. Hence, these areas are deemed ecologically fragile. Spatially, cultivated lands in the humid zone of Eastern China region consistently showed high sensitivity, while vegetation sensitivity in semi-arid regions fluctuated notably with the seasons, peaking in spring. On a seasonal scale, the sensitivity index of grasslands in regions such as Tibet and the northern Inner Mongolia Plateau peaked in spring, while in summer, higher vegetation sensitivity was concentrated in the cultivated lands of the humid Central China region. The spatial distribution of vegetation sensitivity in China demonstrated significant heterogeneity. Therefore, a quantitative analysis of vegetation sensitivity to climate change provides a solid scientific foundation for decision-making regarding ecological environment protection and mitigation strategies, helping to reduce the adverse impacts of climate change in China.