Positioning, navigation, and timing (PNT) serves as a fundamental component of national critical spatiotemporal infrastructure and a cornerstone of national security. It provides essential support for promoting new-quality productive forces and combat capabilities in emerging domains, while also becoming a strategic high ground contested by major powers. As global PNT governance enters a pivotal period of regulatory transformation, a significant window of opportunity has opened for China to deepen its engagement in international PNT rule-making and strengthen its voice in global governance. This study examines the strategic importance of PNT, surveys the evolving legal and regulatory landscapes in the United States, the European Union, and China, and analyzes major trends in the evolution of international PNT rules, including the transition from technology-oriented regulation to comprehensive governance, from single-system dependence to multi-source integration, from Earth-based applications to cislunar, deep-space, and deep-sea domains, and from rule-making dominated by a few major powers to broader multi-stakeholder participation. Based on this analysis, the study proposes that China should accelerate the development of a comprehensive PNT legal and regulatory framework, strengthen security risk prevention mechanisms, promote the internationalization of PNT standards, and engage more proactively in the formulation of international PNT rules. These measures will enhance China's discourse power in global PNT governance and provide stronger legal support for safeguarding national spatiotemporal security and advancing the high-quality development of the national comprehensive PNT system.