This thesis analyzes the security risk of the municipal e - govemment network of chengdu , reports the specific security demands of the network , and defines the objectives of the network . applying the modem security theory and technology , build an integrated secure network with multi - layer protocol and multi - level structure . and design a security management plan which is very import in the whole security system 在信息安全理論和安全技術框架指導下,運用信息系統安全工程方法,針對協議層次和縱向結構層次的不同安全要求,設計具有一定創新的綜合安全體系,將物理安全、環境安全、操作系統安全、通信安全、傳輸安全、應用安全、用戶安全以及安全管理等相結合,構成層次清晰、功能精干強健的安全體系。