In response to the strategic imperative of “conducting audit centered on the Overall National Security Concept”, this article explores the internal logic propelling the functional evolution of national audit from risk revelation to security governance. This analysis is grounded in a comprehensive review of the over-forty-year development of national audit, with particular emphasis on the deepened exploration of security maintenance since 2014. Traditional national audit, constrained by micro-level verification, often fails to address the cross-domain and systemic governance demands of the modern era. Rooted in the holistic philosophy and the preventive wisdom of “treating potential diseases” in the Chinese civilization, we map the historical trajectory of national audit as it expands from maintaining economic order to safeguarding overall national security.The study constructs a “politics-economy” bidirectional interaction mechanism to elucidate the closed-loop logic of national audit. Acting as a routine “economic check-up”, national audit not only facilitates the downward transmission of political intent but also ensures that economic risks are traced and fed back upward along the “funds-projects-policies-politics” chain. Regarding implementation, the paper identifies research-oriented audit as the primary engine. By anchoring in economic supervision and cultivating elite professional teams (“special forces”), audit institutions can erect a three-dimensional “point-line-plane” security barrier. This structure integrates micro-foundations, transmission chains, and macro-governance systems. This functional shift intends to theoretically substantiate national audit practices, steering national audit toward active security governance while contributing original support to China’s autonomous knowledge system in auditing.