信息安全问题是当前在涉密信息系统建设和使用中面临的首要问题。为提高涉密内网的安全性,防止敏感信息泄露,分析了当前在涉密内网中信息安全方面所面临的主要威胁和产生原因。针对这些方面,并结合实际建设经验,从身份认证、入侵防御、安全审计、漏洞扫描和病毒查杀等多个方面,对涉密内网中信息安全防护体系的建设进行了探讨。实践证明,通过多方面的综合改造和建设,能够取得较好的效果,有效提升了网络的安全防护水平。 Information security is the most important issue in the construction and use of classified information system. In order to improve the security of the classified network and prevent the leakage of sensitive information, the main threats and causes of the current information security in the classified network are analyzed. In view of these aspects, combined with the actual construction experience, from the authentication, intrusion prevention, security audit, vulnerability scanning and virus killing and other aspects, the construction of information security protection system in the classified network is discussed. Practice has proved that through comprehensive reform and construction in various aspects, we can achieve better results and effectively enhance the level of network security.