Under the backdrop of global climate change, vegetation resilience is crucial for maintaining ecosystem stability and functional continuity. The Qilian Mountains National Park, serving as a significant ecological barrier in the northeastern Qinghai-Tibet Plateau, hosts a complex ecosystem that is highly susceptible to climate fluctuations and extreme weather events, necessitating systematic monitoring of its vegetation resilience and exploration of climate-driven factors. However, existing studies in this area remain insufficient. The autocorrelation coefficient, first-order autoregressive model (AR(1)) indicator, compared to other resilience assessment models, effectively handles the cumulative effects of disturbances and provides early warning signals for critical transitions. This study employs the AR(1) indicator to analyze the spatiotemporal characteristics of vegetation resilience in Qilian Mountains National Park from 2002 to 2021 and explores its potential climate drivers using a random forest model. The results indicate that: (1) Temporally, vegetation resilience exhibited a "U-shaped" change, with May 2011 marking a significant turning point. (2) Spatially, resilience declined significantly in the desert areas of the western and central sections, while the forested areas on the eastern edge showed improvement. (3) Despite the enhancement of greening trends, resilience demonstrated a declining trend in the last decade, revealing the underlying vulnerability of the ecosystem. (4) In the first decade, resilience was mainly driven by precipitation, while in the latter decade, temperature became the dominant factor, with rising temperatures and the consequent intensification of droughts being critical contributors to the decline in resilience. The study highlights the inconsistency between resilience and greening trends, underscores the importance of incorporating resilience indicators into ecological health assessments, and explores the applicability of critical slowing down theory-based assessment methods in ecological management. This research provides scientific evidence for park management and ecological conservation and holds reference value for studies in other ecologically vulnerable regions.