Resource curse and environmental regulation are the key bottlenecks that hinder the sustainable development of the resource industry. A reasonable assessment of the decoupling relationship between resource supply, environment regulation and resource industry transformation is helpful to promote the decision-making of industrial restructuring in post-development regions. Taking Inner Mongolia Autonomous Region of China as the research object, panel data related to resources, environment and industry from 2010 to 2021 are selected to evaluate the spatial and temporal evolution of regional resource supply security, environmental regulatory pressure and resource industry transformation efficiency, measure the decoupling index among the factors, and use geographic detector technology to identify the constraints affecting factor decoupling. The results show the following: (1) the resource curse effect of Inner Mongolia is not significant, and some resource industries have prominent advantages; (2) the security of resource supply and the transformation efficiency of the resource industry show overall upward trend, the pressure of environmental regulation is basically balanced, and the development level of factors in resource-endowed regions and central cities is relatively high; (3) the spatial and temporal evolution of the decoupling relationship between resource supply, environmental regulation and resource industry transformation is uncertain, and the resilience of regional economic and social governance is poor; (4) resource endowment and resource industry advantages are the key that restricts the decoupling of factors, and the cumulative effect of ecological governance is likely to lead to the randomness of the decoupling of environmental regulation and resource industry transformation. In addition, this study suggests that the post-development areas should pay attention to the classification of resource industry relief, trans-regional economic and social collaborative governance and special resources exploitation.