Abstract: Combining with the layers of protection analysis (LOPA), through the establishment of event tree model which analyzes the human exposure probability relations with independent protective layers, and combining with the analysis of larger and major accident in correction factors of human exposure probability, make the LOPA analysis get more accurate results in risk analysis and formulate corresponding risk control activities.

摘要： 本文结合保护层分析方法（LOPA），通过建立事件树模型分析了人员暴露概率的取值与独立保护层的关系，并结合具体案例对较重大事故的分析中人员暴露概率的取值修正依据，使LOPA分析人员能得到更准确的风险分析结果，并制定针对性风险管控活动。

关键词: 保护层分析(LOPA) SIL评估 人员暴露概率 过程安全管理 修正因子, Layers of Protection Analysis (LOPA), SIL Evaluation, Human Exposure Probability, Process Safety Management, Correction Factor