In recent years, cross-border data flow has become the new normal of digital economy. As the legal control of cross-border data flows by various nations produces new types of trade barriers and obstructs the release of global economic vitality, the topic of trade regulation of cross-border data flows has increasingly gained broad attention. The trade regulation of cross-border data flow at the global level is faced with a balance problem between the two regulatory objectives of good data protection and free data flow. This involves a number of interests, including personal privacy, national security, and free flow of data. Currently, due to the social, cultural, political, and economic variations between each country, it is challenging to come to an agreement on the value judgment of the regulatory objectives. For trade regulation of cross-border data flows, reducing differences between various regulatory objectives becomes a crucial task. The exception clause, as a flexibility rule, with special institutional function, can harmonize various regulatory objectives, achieve the compatibility effect of a dynamic balance among various regulatory objectives, and lessen the tension between the need for public policy reservations and the development of an open digital trade environment. The exception clause is an important part of cross-border data flow trade regulation, mainly including three types of WTO exception clauses, CPTPP exception clauses, and RCEP exception clauses. The way exception clauses are designed under various paradigms differs greatly in terms of structure, language expression, conditions of application, etc., as well as their ability to balance and harmonize the degree to which various regulatory objectives can be met. Each has its own advantages, but it also faces different degrees of difficulty and uncertainty in application. China’s participation in the construction of new rules for cross-border data flow has become an unavoidable task, and we should make full use of the institutional functions of exception clauses to enhance the export capacity of China’s institutional discourse power. In the choice of exception clause paradigm in China, first, based on the intrinsic benchmarks, it is necessary to improve domestic digital rule of law, clarify the basic position of cross-border data flow regulation, seek system coordination effects, and avoid vicious system competition. Second, it is necessary to seek external strategies and adhere to the gradual strategy of functional transformation, and develop from pursuing loose or vague exception clauses to clear exception clauses and gradually from pursuing pragmatic and flexible contract cooperation to binding rule cooperation.