With the development of 5G, artificial intelligence, blockchain, big data and other digital technologies, ASEAN has begun to pay attention to the impact of the development of the digital economy in the region, in which the security of cross-border data flow has increasingly attracted the attention of ASEAN and its member countries. This article uses qualitative research methods such as literature review to summarize the construction process and rules of cross-border data flows in ASEAN and its major member countries, in order to analyze the problems in ASEAN’s cross-border data flows rules and the challenges they pose to China-ASEAN’s cross-border data flows cooperation. The study found that ASEAN has formed a three-layer rules system from macro to micro in the field of cross-border data flows. Major member countries such as Singapore apply diverse rules to strengthen international integration, while Malaysia will allow cross-border data flows to be included in the “exceptional situation”. At the same time, it is believed that the application of rules within the ASEAN region is relatively chaotic, and the difficulty of internal coordination will increase the compliance costs and potential risks of Chinese enterprises conducting cross-border data flows in ASEAN. Therefore, relevant suggestions are proposed to refine the operational path of China-ASEAN data cross-border flows, strengthen mutual recognition of China-ASEAN data security rules, and explore new ways of China-ASEAN data cross-border flows.