The development of digital trade is an essential requirement for China to become a strong trading nation. Currently, data has become a key resource for reshaping the structure of the global economy, and cross-border flow of data has become a key factor in promoting digital trade. Under the cooperation on cross-border flow of data, the US and EU have gone through the Safe Harbor Agreement, the Privacy Shield Agreement and the Data Privacy Framework. Despite numerous setbacks, these efforts have gradually established a transatlantic cooperation mechanism for cross-border data flows. However, significant differences between the U.S. and the EU—particularly in terms of their value orientations and legislative systems for data protection—remain major obstacles to deeper cooperation. Nevertheless, given the high level of mutual interdependence between the U.S. and EU digital trade markets, ongoing negotiations have progressively refined and institutionalized their cooperation framework. A comprehensive examination of the evolution and key features of the U.S.-EU cross-border data flow cooperation over several decades can offer valuable insights for China as it seeks to enhance its own mechanisms for international data flow governance, advance digital trade, and further support the strategic goal of becoming a major trading power.