Objective Frequent geopolitical conflicts heighten the vulnerability of the global natural gas trade. Establishing a robust emergency regulation and supply framework is essential for national energy security.

Methods A demand-side regulation and supply security model for natural gas under extreme conditions is proposed to achieve precise allocation across provinces and sectors. First, three methods are innovatively introduced, including the inoperability input-output model, the complex network theory, and the Bayesian probability updating method. They are used to construct a comprehensive evaluation index system for sector importance. The system covers three dimensions: macroeconomic impacts, structural importance of the network, and livelihood impacts. Second, a two-stage multi-objective optimization model is built to minimize three-dimensional comprehensive losses. At the upper level, an improved non-dominated sorting genetic algorithm performs Pareto optimization of sector regulation schemes at the national level. At the lower level, national schemes are precisely decomposed to provincial regions using an iterative “bottom-line priority and surplus sharing” allocation rule.

Results Three natural gas import disruption scenarios of varying severity are simulated using 2023 input-output and energy statistical data. The results indicate that: (1) Under a mild shortage, supply security prioritizes maximizing marginal benefits, achieving supply-demand balance through minor adjustments in energy-intensive industries. (2) Under a moderate shortage, regulation relies heavily on high-consumption, large-scale basic industries, revealing regional disparities in supply security. Heavy-chemical provinces (e.g., Shandong and Yunnan) undertake more supply security responsibilities to protect core high-tech industries in other provinces. (3) Under an extreme shortage, resource allocation concentrates strictly on critical social functions — such as public livelihood, healthcare, oil and gas production, and pharmaceutical manufacturing — further intensifying regional differentiation.

Conclusion Recommendations include refining, quantifying, and dynamically updating the natural gas demand-side emergency regulation mechanism. An inter-provincial benefit compensation framework should also be established. Differentiated consumption guidance should then be implemented based on sectoral importance to enhance demand elasticity.