Abstract: In view of the scattered and isolated security protection strategies of the nuclear reactor industrial control system and enterprise information system interconnection projects, this paper conducts a detailed analysis of the security and confidentiality risks at the management level and the technical level with the consideration of the security and confidentiality requirements of the system interconnection. On the basis of the analyzed results, this paper proposes a security interconnection protection system based on the management and technology dual defense, which provides a guide for the construction and implementation of the interconnection of a nuclear reactor industrial control system and a enterprise information system.