Abstract: The Shanxi-Shaanxi-Inner Mongolia Region is characterized by a multi-energy coordinated development pattern, resulting in diverse carbon emission sources and pronounced spatial clustering. Under the long-term constraints of the “dual-carbon” goals, investigating carbon footprint measurement and its driving mechanisms can provide a scientific basis for region-specific, tiered low-carbon mitigation and coordinated governance. In this study, a carbon footprint accounting model is developed by integrating “NPP-VIIRS-like” nighttime light data, Carbon Emission Accounts and Datasets（CEADs）, net primary productivity, and China Land Cover Dataset（CLCD） to estimate the carbon footprint of the Shanxi-Shaanxi-Inner Mongolia Region from 2000 to 2021. Exploratory spatiotemporal data analysis is applied to reveal the spatio-temporal evolution of carbon footprints. An improved Tapio decoupling model is used to assess the dynamic relationship between economic growth and carbon-environmental pressure, and a multiscale geographically weighted regression model is employed to identify the spatial heterogeneity of influencing factors. The results show that the cumulative increase in carbon footprint in the study area reaches 791.810×10⁴ km², with an average annual growth rate of 11.930%. Carbon footprints at both the provincial and municipal（league） levels exhibit an overall upward trend, with marked interprovincial and intercity disparities. A small number of cities maintain persistently high carbon footprint levels, and this pattern intensify over time. At the municipal（league） scale, carbon footprints show significant positive spatial autocorrelation, and some agglomeration patterns remain stable over the long term. From 2000 to 2021, the relationship between economic growth and carbon-environmental pressure in the study area evolve from predominantly weak decoupling to a stage characterized by the coexistence of multiple decoupling states. Energy consumption intensity and economic development consistently exert positive effects on carbon footprint growth in most cities. By contrast, the effects of industrial structure, urbanization, and government intervention display strong regional heterogeneity. Natural environmental factors generally contribute to carbon footprint reduction, although the magnitude and direction of their effects varied across cities. These findings provide empirical support for differentiated emission reduction strategies in the Shanxi-Shaanxi-Inner Mongolia Region and offer useful reference for promoting green and low-carbon transformation in resource-based areas and advancing the “dual-carbon” goals.