Restrictions on cross-border data flows and enterprise supply chain risks are closely linked. Based on data of listed enterprises from 2015 to 2023, this study constructs an enterprise-level index of restrictions on cross-border data flows and empirically examines the impact of such restrictions on enterprise supply chain risks. The findings indicate that restrictions on cross-border data flows significantly increase enterprise supply chain risks. Heterogeneity analysis reveals that the adverse effects of these restrictions on supply chain risks are particularly pronounced for enterprises in eastern China, enterprises with medium-low competitiveness, private enterprises, and highly digitally intensive enterprises. Mechanism tests show that restrictions on cross-border data flows exacerbate enterprise supply chain risks through channels such as increasing enterprise costs, reducing the efficiency of enterprise resource allocation, and inhibiting enterprise technological innovation. From the perspective of restrictions on cross-border data flows, this study comprehensively reveals their adverse impacts and internal mechanisms on enterprise supply chain risks, providing empirical evidence for effectively alleviating such restrictions, mitigating enterprise supply chain risks, and enhancing enterprises' supply chain control capabilities.