With the development and popularization of network technology, network security issues are increasingly being valued. The application of knowledge graph technology in network security can significantly enhance the level of protection, assist users and relevant departments in understanding overall trends of network security vulnerabilities, and swiftly identify and respond to security threats. To improve the analysis and response capabilities to network security threats, developing methods for identifying key nodes in the network is urgent. This research focuses on the degree centrality calculation method for nodes in a network security database based on knowledge graphs. We propose a novel approach for computing node degree centrality within a knowledge graph‐based network security database. The method comprises two main components: weight calculation and score calculation. Additionally, we have developed a node importance ranking module based on a network security knowledge graph derived from the CVE database, providing a faster and more accurate solution compared to manual methods. We then discuss the significant application value and promising development prospects of the knowledge graph‐based node degree centrality calculation method in the field of network security protection in future work.