通过系统理论过程分析（system-theoretic process analysis, STPA）方法识别航空事故危险因素，属于定性分析过程，无法定量地评估各因素对事故的影响程度。针对上述问题，提出STPA与贝叶斯网络（Bayesian network, BN）结合的定性与定量分析方法。以捷蓝航空A320飞机襟翼事故为例，通过STPA方法构建了襟翼控制系统的控制结构模型并全面地分析了潜在的不安全控制行为及相关致因场景。随后将STPA定性分析结果转化为可定量分析的贝叶斯网络模型，从而识别出事故中的内部交互逻辑以及影响度较高的致因因素，提出全面的安全性建议。分析结果表明：导致事故的主要因素为液压源故障，而动力传输组件（power transmission unit, PTU）故障和液压管路泄漏是导致液压源失效的主要原因，关键重要度分别为0.688和0.299。

The identification of aviation accident risk factors through the system-theoretic process analysis (STPA) method is a qualitative analysis process that does not allow for a quantitative assessment of the extent to which each factor contributes to an accident. To address the above problem, a qualitative and quantitative analysis method combining STPA and Bayesian network (BN) was proposed. Taking the JetBlue A320 aircraft flap accident as an example, the control structure model of the flap control system was constructed by STPA method, and the potential unsafe control behaviors and related causal scenarios were analyzed comprehensively. Then, the results of STPA qualitative analysis were transformed into a Bayesian network model that could be quantitatively analyzed, so as to identify the internal interaction logic and the highly influential factors in the accident, and put forward comprehensive safety recommendations. The analysis results show that the main factor leading to the accident is the failure of hydraulic source, while the failure of power transmission unit (PTU) and the leakage of hydraulic line are the main causes of hydraulic source failure, with a critical importance of 0.688 and 0.299, respectively.