The governance of cross-border data flow is of great significance for optimizing the business environment and promoting the development of digital economy and digital trade. At present, the governance of global data cross-border flow is characterized by strong supervision and fragmentation, and all countries in the world are actively optimizing their own data cross-border flow supervision on the premise of effectively maintaining data security and personal privacy protection. In view of the problems existing in the governance of data cross-border flow in China, such as insufficient overall planning of data cross-border flow supervision and development of digital trade, single supervision mode of data cross-border flow, the support of data cross-border flow supervision policies to help optimize the business environment, together with the circle of friends of data cross-border flow in China needs to be expanded, and the innovation of data cross-border flow supervision policies in special areas is insufficient, the paper puts forward some measures such as establishing data cross-border flow supervision institutions, perfecting data cross-border flow legislation, establishing a white list mechanism of data cross-border flow, optimizing the digital business environment, and exploring the establishment of special supervision policies for data cross-border flow in China etc.