Abstract: Natural gas underground gas storage serves as the core hub of the"production-supply-storage-sales"system in the natural gas industry chain. Its operational stability is vital to energy supply security, public safety, and environmental sustainability. The 2015 Aliso Canyon gas leak in California exposed prominent loopholes in the safety supervision of U. S. underground gas storage, prompting a comprehensive restructuring of the federal supervision system. The safety supervision framework established by the U. S. Pipeline and Hazardous Materials Safety Administration(PHMSA)was examined as the primary research object. Following a systematic review of safety supervision documents established for underground natural gas storage after the accident, the development context, key contents, implementation pathways, and technical logic of the documents were analyzed across six dimensions: regulatory legislation, management system, on-site assessment, inter-agency research, official consultation, and industrial standards. After the system 's core characteristics were summarized and its effectiveness was quantitatively evaluated, actionable optimization recommendations aligned with China 's underground gas storage infrastructure realities were proposed. Results indicated that PHMSA 's four-pronged strategy-legal foundation, institutional empowerment, technological support, and collaborative coordination-creates a full-lifecycle supervision model that has significantly enhanced the safety of U. S. underground natural gas storage. These findings offer valuable insights for improving China 's regulatory framework in this critical sector.