Abstract: Public law has long been a “public law taboo” for extraterritorial application because of its inherent territorial nature, especially the traditional public law. The advent of the Legal Binding Instrument marks the beginning of the connection of the traditional private international law issue of transnational jurisdictional coordination with the traditional public law represented by criminal law, which represents a new breakthrough in the extraterritorial application of public law. However, both the current progress of the negotiation of this legal instrument and the degree of development of international law theory of jurisdiction, indicating that this breakthrough is only the beginning of this trend. At this stage, the Legal Binding Instrument also lacks a realistic basis to function in practice, and the extraterritorial application of traditional public law is still restricted, the development of which will be a long process.