Abstract: The current multi-level security model is lack of security mechanism for information on the visit process.Based on trusted computing technology，the UCON（Usage Control） model is improved to construct a multi-level security model which considers both confidentiality and integrity.The improved model can protect the security of information throughout the whole visit process，and the integrity verify policy is used to meet the integrity of information.The improved model can also facilitate security administrators to choose proper security policy according to the application，which increase the flexibility of the system.

Key words: multi-level security, trusted computing, Usage Control（UCON）

摘要： 针对当前多级安全模型在访问过程中缺乏信息安全保护机制的不足，基于可信计算技术对使用控制模型进行改进，实现保密性和完整性两者兼顾的多级安全模型。改进模型将在整个访问过程中对信息的安全性进行保护，并运用完整性验证策略保护信息的完整性，同时方便安全管理员根据管理需要，对安全策略进行调整，提高了系统的灵活性。

关键词: 多级安全, 可信计算, 使用控制