Quantifying the fossil energy-related sectoral vulnerability and the impact paths along China’s supply chains

China’s sectors are heavily reliant on fossil energy. How to accurately quantify sectoral vulnerability and the risk impact paths after adaptive adjustments is a crucial topic for energy supply chain security. Therefore, this study employs an integrated analytical framework (IAF) that combines the input–output model, the linear programming model, and structural path analysis to quantify the economic vulnerability of various sectors in China to the intersectoral flow of fossil energy (crude oil, natural gas, and coal) from both production-based and consumption-based perspectives. Additionally, it simulates the mitigation of negative shocks through optimal allocation strategies under resource-constrained scenarios, thereby identifying impact paths across sectors. The results show that the most vulnerable sectors for crude oil, natural gas, and coal are refined petroleum refining and nuclear fuel, other social services, and electricity and heat production and supply, respectively, from a production-based perspective. However, from a consumption-based perspective, the final uses of certain services (e.g., the public administration, social organizations and business services) are more vulnerable to supply disruptions. Furthermore, capital formation and residential consumption are critical drivers of fossil energy use within the framework of optimal allocation strategies. These findings provide valuable strategic insights for economic policymaking in the context of resource scarcity.