Abstract:In order to explore the solution of the problems of the short of knowledge and immature theoretical research about large scale,specifically wide-area,quantum key distribution network research,the structure model,the secret key model and the active model of the trusted relaying quantum key distribution network were proposed from the viewpoints of structure,inner secret key relationship and working principle respectively for the trusted relaying quantum key distribution network which is the only real practical one so far.Firstly,from the viewpoint of system theory,the quantum key distribution network was divided into five layers according to the basic principle of key relaying based on the existing structure model.The constitution of each layer and the relationship between them were explained in detail.Secondly,from the viewpoint of information theory,the quantum key distribution network was abstracted as a key information graph according to the key sharing relationship among all nodes and the node and edge were formally defined.Therefore,the secret key information in the five layers quantum key distribution network could be explained by the graph theory in details.Lastly,from the viewpoint of the cybernetics, the key distribution process was resolved into two basic parts of key relationship establishment and secrete key generation,then the works of the quantum key distribution network could be explained by the development of key information graphs.The analysis showed that the proposed quantum key distribution network model can achieve the goal of hierarchical,parallel and pipelining key distribution,and can ensure the security of key distribution,which establishes the foundation for the future theoretical and technology research.