With the rapid development of computer network and information technology, emerging technologies have been widely applied in the electric power industry. Following the relevant documents and specifications of the country and the electric power system, the electric power information system is divided into two network areas: the information intranet and the information extranet. In these two areas, applications with different security levels are deployed to meet the business needs of different security levels. While the openness of the network brings great convenience to people, it also brings network security problems such as system intrusion and information leakage. Aiming at the threat of Internet application security, drawing on the current cutting-edge technology of network security, and combining the application requirements of internal and external network data exchange, research on internal and external network data security exchange technology is carried out. Based on the principles of real-time, accuracy and security of data transmission and access, following the design concept of comprehensive network security protection, a multi-level isolation protection and security strategy for strong control of data exchange are proposed, and an internal and external network security exchange platform, data exchange system, and security control method that meet the requirements of power grid applications are designed. This architecture design has high security and efficiency, not only meeting business requirements technically, but also proposing a comprehensive system security plan, formulating clear network security policies and strategies, and establishing a complete network security framework. It has been well applied in data exchange scenarios of the internal and external network of the power information system.