在安全级格模型、BLP、Biba安全模型的基础上,为解决信息系统对信息安全性的要求,针对传统BLP模型的多级安全策略并没有阻止信息的非法修改的弱点,利用现有Petri网数学模型,结合网络应用,对强制访问控制模型进行分析研究,对模型的安全性进行验证,实践证明,能够有效地改善信息系统的总体安全策略。 Based on the security grid model, BLP and Biba security model, in order to solve the information system’s requirement of information security, the multi-level security policy against the traditional BLP model does not prevent the weakness of the illegal modification of information. By using the existing Petri net Mathematical model, combined with the application of the network, analyzes and studies the mandatory access control model, verifies the security of the model, and proves that it can effectively improve the overall security strategy of the information system.