Abstract: This paper introduces the meaning of security components composition intensity analysis，studies the methods in existence，discusses the security characteristic of security components composition at the condition of security boundary existed.After analyzing the method of Pro.DUAN，a new method based on Petri net is introduced.In addition，the paper introduces the information system modeling in Petri net，in order to prove the new method，simulates the new method on ExSpect.

摘要： 介绍了安全组件组合安全强度分析的现实意义，对现有方法进行研究，重点探讨了安全边界已知情况下安全组件组合的安全特性。研究段云所副教授所提出的理论，并以其方法为基础，提出了一种基于Petri网的网络系统安全组件组合强度分析方法，进一步研究了Petri网模型的构造，并利用Petri网仿真工具ExSpect对所提出方法的正确性进行仿真验证。