The invention belongs to the technical field of communication, and particularly relates to a system and a method for realizing data transmission between the Internet and a public security intranet. The system comprises a first data service bus, a second data service bus and a public security boundary platform connected between the first data service bus and the second data service bus, wherein theplurality of first users are connected to the plurality of second users through the first data service bus, the public security boundary platform and the second data service bus in sequence so as torealize unified interaction between the Internet and the public security intranet; the data service bus comprises service providing, service monitoring, service management and shared data exchange. Data transmission reliability and integrity are realized, and unified specification, unified standard, unified monitoring and unified service of data transmission are ensured.