Against the backdrop of the vigorous development of the digital economy, cross-border data flow has become a pivotal driving force for regional economic cooperation and development between China and the Association of Southeast Asian Nations (ASEAN). Nevertheless, the contradiction between sovereign security and digital freedom has become increasingly prominent, and how to balance the relationship between the two and construct an effective collaborative path for regulation has emerged as an important issue demanding urgent resolution. ASEAN is situated at the hub of China’s construction of the Digital Silk Road, and advancing collaboration between China and ASEAN on cross-border data flow constitutes a mutually beneficial and win-win initiative. It is therefore necessary to conduct an in-depth study on the paths for China-ASEAN digital governance cooperation. At present, the advancement of regulatory collaboration on cross-border data flow between China and ASEAN is underpinned by practical foundations in aspects such as economic complementarity, institutional frameworks and strategic alignment, and also supported by realistic demands in fields including industrial development and data security. Taking the legal provisions on cross-border data flow formulated by ASEAN as an organization, individual ASEAN countries and China as the starting point, conducting systematic collation and in-depth analysis can help summarize the incoherencies existing in the legal regulatory frameworks between China and ASEAN. By exploring the underlying deep-seated causes of such “incoherencies in legal regulation”, this paper proposes that a collaborative path for the regulation of China-ASEAN cross-border data flow can be constructed from four dimensions: promoting the coordination of legal regulation and mutual recognition of standards, implementing hierarchical and classified governance, strengthening regional governance mechanisms and trust-building, and enhancing regional autonomy.