Strengthening the security supervision of archives cross-border transfer is an essential measure for China to enhance the effectiveness of archival security governance and participate in preventing and resolving non-traditional national security risks. Using methods such as literature research, policy text analysis, expert interviews, and online surveys, this paper deeply explores the current situation of security supervision of archives cross-border transfer in China. China's security supervision of archives cross-border transfer faces four major dilemmas: the need for optimization of regulatory basis, unclear boundaries of authority and responsibility, imperfect implementation rules, and a need for improvement in the level of intelligence. To promote the modernization of archival security governance through the security supervision of archives cross-border transfer, it is necessary to firmly establish a bottom-line thinking of archives cross-border transfer, and achieve safe and effective governance supervision; improve the regulations and standards of archives cross-border transfer, and promote legal compliance supervision; define the responsibilities and powers of archives cross-border transfer supervision, and promote multi-faceted collaborative supervision; analyse the business situation of archives cross-border transfer, and carry out graded and classified supervision; build a supervision platform of archives cross-border transfer, and ensure credible and intelligent supervision.