Abstract: Through policy-based network security management research, this paper analyzed the existing network security policy conflict detection and resolution method shortcomings. Based on policy refinement of ideas and security policy conflicts classification technology, policy-based network management security-level model was established, with extended XACMI_ language description. According to the relationship between policy behavior, using knowledge reasoning,dynamic layered security corresponding level of policy refinement consistency automatic detection and timely conflict resolution were made, letting it has a good reusability and scalability, and is conducive to the improvement of management efficiency. Policy-based access control refinement application implementation was verified. Finally, some of the fulure research directions were discussed.

Key words: Network security, Policy refinement, Security-level model, Consistency of automatic detection, Knowledge reasoning,Conflict resolution