ABSTRACT With the rapid development of the Internet, human beings have entered into the era of big data. Data has become an important production factor and social wealth, and countries have added data governance into a national strategy. Data naturally flows across borders, and data gains value through mobility, so international regulation of cross-border data flows becomes necessary. At present, the legal norms for cross-border data flow have experienced a gradual evolution at the international and national levels, and soft law and hard law coexist. However, there is no existing common legal standard for cross-border data flows to comply. In particular, the cross-border data flows is facing the biggest challenge called data localization. Data localization has certain rationality, which can protect the data security of the country to a certain extent, but it also brings many problems. It leads jurisdictional conflicts, and may generate data protectionism, which is not conducive to the stable development of global cyberspace. The demand for cross-border flow of data is closely related to trade, and the most binding trade rules in the world are part of WTO. Although there are no rules in the WTO specifically for cross-border data flow, there are related rules can be applied to cross-border data flows, such as GATS. This means that the possibility of establishing binding international standards governing cross-border data flows exist. As the data is diverse and cross-cutting, this dissertation believes that the data should be classified reasonably. Then, the diverse set of data should be differentiated in legislation to prescribe appropriate regulation. Meanwhile, cross-border data flows require a secure and fair network environment that enhances national trust and helps to eliminate the obstacles due to the irrationality of data localization measures. Countries need to break through the conflicts of data jurisdiction, vigorously promote the international cooperation of cyberspace law enforcement, and create a good legal framework for facilitating the cross-border data flow. Keywords: Personal Data, Non-personal Data, International regulation, Cross-border data flow, Data localization, Digital trade