An increase in black carbon (BC) column concentration intensifies atmospheric warming, alters precipitation regimes, and accelerates glacial melting, posing substantial risks to regional climates and ecosystems. This study systematically evaluated the applicability of MERRA-2 reanalysis data over China by using daily-scale BC column concentration observations from AERONET sites. By integrating multi-source remote sensing data with machine learning models, a high-precision BC column concentration dataset for China was reconstructed. The results show that MERRA-2 data exhibit significant limitations in the China region, with an overall correlation coefficient (R) of only 0.54, an RMSE of 6701 μg/m², and only 41 % of the sites demonstrating high correlation. For the high-quality data, R is 0.44, with an RMSE as high as 9112 μg/m²; the poorest performance is observed in the medium and low-quality data, with an R of 0.21. In contrast, the constructed model increased R by 0.29 and decreased RMSE by 2396 μg/m² across the entire dataset, with the number of sites showing good correlation improving by 34 %. For the high and medium-quality data, R ranged from 0.70 to 0.86, and the RMSE decreased by 1475—4569 μg/m². In addition, MERRA-2 BCE column concentration and BC aerosol optical depth are the key factors in the model, while surface-level PM_2.5, organic matter, and BC concentrations are also important variables. Spatiotemporal evolution analysis shows a high degree of spatial overlap between regions with elevated BC column concentrations and China's key national urban agglomerations as well as major energy corridors. From 2001 to 2023, the national BC column concentration exhibited a trend of initial increase followed by a steady decline, with an average annual decrease of 42.36 μg/m². Significant emission reduction achievements were observed in the central and eastern regions, while high concentrations persist in the western region. This study provides a critical data and technical foundation for both regional climate research and atmospheric environmental governance.