Satellite-observed vegetation greening is regarded as direct evidence of reclamation in open-pit mines. However, improvements in vegetation greenness do not necessarily indicate ecosystem resilience recovery. Identifying hidden areas of fragile resilience beneath apparent greening remains a critical challenge. In mining areas, extracting vegetation disturbance signals required for resilience assessment is difficult, because varying reclamation cycles and high spatial heterogeneity often lead to spectral mixing in existing decomposition methods. Therefore, we proposed VegDecouple, a decoupling method that adaptively separates background vegetation dynamics from short-term disturbances in mining areas. Using Landsat NDVI data (1990-2025) from a typical open-pit coal mine on the Loess Plateau, we characterized the heterogeneous trajectories of the variance-based resilience proxy beneath greening, identified three reclamation patterns, and quantified the effects of key drivers. The results showed that (1) VegDecouple effectively separated disturbance and steady-state components from non-stationary vegetation signals in mining areas. Compared with existing methods, it delivered the best spectral decoupling performance, achieving the highest energy capture and the lowest leakage. (2) Vegetation greenness and the resilience proxy exhibited pronounced temporal asynchrony and spatial mismatch. Three reclamation modes were identified within greening areas, revealing distinct inferred ecological recovery pathways. (3) Background vegetation state, reclamation age, and mean growing-season temperature showed the largest cumulative SHAP contributions, exceeding 75 % across the three reclamation modes. Moreover, SHAP dependence plots revealed nonlinear associations between key drivers and the resilience proxy. Beyond the case study, VegDecouple performed robustly across mining areas under contrasting climatic conditions. These findings provide a transferable framework for identifying potential degradation risks and supporting differentiated management in reclaimed mining landscapes.