Vegetation restoration potential (VRP) represents the attainable upper bound of vegetation recovery under existing environmental and habitat constraints. Quantifying VRP is essential for identifying restoration priorities and evaluating the long-term sustainability of global greening under accelerating climate change and widespread land degradation. However, the global spatial patterns, dominant drivers, and regional disparities of VRP remain insufficiently understood. We integrated multi-source remote sensing and environmental datasets to assess the spatiotemporal dynamics of VRP and vegetation restoration potential achievement degree (VRPAD) from 2000 to 2022 under similar-habitat conditions, and applied the Local Indicator of Stratified Power (LISP) to characterize the spatial heterogeneity of dominant drivers. Results showed that global kernel normalized difference vegetation index (kNDVI) increased significantly, with greening hotspots concentrated in eight major regions, whereas VRP declined significantly at-0.01 per decade (10a). High VRP values were mainly distributed in Eastern Europe, South Asia, Southeast Asia, and Central Africa, whereas low values occurred in arid-semiarid and high-latitude regions. Global VRPAD increased significantly at 0.03 per decade (10a), particularly in tropical and subtropical regions, indicating progressive realization of restoration potential but persistent constraints in dry-lands and cold environments. Climatic factors dominated the global spatial pattern of VRP, with solar radiation (SR), precipitation (PRE), and temperature (TEM) jointly explaining 81.22% of the land surface. SR showed stronger control in low-latitude arid and plateau regions, PRE was more influential in tropical monsoon and temperate humid regions, and TEM exhibited stronger explanatory power in mid-to high-latitude plateaus and temperate steppe regions, whereas topography and land use exerted stronger localized effects. These findings indicate that recent global greening has been accompanied by a contraction of remaining restoration space and that restoration outcomes are strongly constrained by regional environmental endowments. This study provides a global benchmark for identifying restoration priority areas and supports region-specific restoration planning and climate-adaptive ecosystem management.