Abstract: With the increasing development of the computer network application, network security is facing the heavy challenge. The international research shows that network security is on the way to trustworthy network (TN). Apart from current security mechanism, the future TN adds behavior trust. TN includes the trust of service providers, the trust of the network information transmission and the trust of end-users. Trust based on user behavior not only can reduce or avoid the contact with the malicious user, but also can reduce the monitoring and prevention additional costs for mutual trust between the service providers and users, so research on user behavior trust will not only improve network security, but also improve overall network performance. In this paper, user behavior trust in trustworthy network is discussed. The authors systematically put forward a framework for evaluation, prediction and control of user behaviors, including reliable evaluation of user behavior trust, trust prediction to meet different prediction combinations of performance and security for service providers, trust and risk decision-making based on game theory, the mechanism based on the RBAC(role-based access control) model through the introduction of user behavior trust, simple and effective user behavior monitoring and prevention strategy based on user behavior trust, etc. Through effective combination of these user behavior trust management mechanisms, the unity of static and dynamic control and the unity of trust and risk, are implemented, which will lay the foundation for further study of the trustworthy network.