对多旋翼电动垂直起降（electric vertical takeoff and landing, eVTOL）航空器推进系统进行了可靠性分析与分配。首先，针对多旋翼eVTOL航空器可靠性历史数据积累不足的问题，使用模糊贝叶斯网络（fuzzy Bayesian network, FBN）建立可靠性分析模型，对其可靠性先验数据进行了补充，并进行可靠性后验推理，辅助定位推进系统关键环节。其次，基于FBN可靠性分析模型，提出一种改进电子设备可靠性咨询组（advisory group on reliability of electronic equipment, AGREE）可靠性分配方法，对不同构型多旋翼eVTOL推进系统进行可靠性分配。结果表明，FBN可靠性分析模型补充了推进系统可靠性数据，可有效识别系统薄弱环节。改进AGREE分配法的可靠性分配结果符合SC-VTOL-01中对eVTOL航空器的可靠性要求，同时该方法得到的可靠性分配结果更为合理，体现了不同构型、子系统、部件间的差异。

Reliability analysis and allocation were conducted on the propulsion system of multi rotor electric vertical takeoff and landing (eVTOL) aircraft. Firstly, to solve the problem of insufficient accumulation of reliability historical data of multi-rotor eVTOL aircraft, a reliability analysis model was established by using fuzzy Bayesian network (FBN) to supplement the reliability prior data, and reliability posterior inference was carried out to assist the key link of the positioning system. Secondly, based on the FBN reliability analysis model of the system, an improved advisory group on reliability of electronic equipment(AGREE) reliability allocation method was proposed. Reliability distribution of eVTOL propulsion systems with different configurations was carried out. The results show that the FBN reliability analysis model supplements the propulsion system reliability data and can effectively identify the system weak links. The reliability allocation results of the improved AGREE allocation method meet the reliability requirements for eVTOL aircraft in SC-VTOL-01, while the reliability allocation results obtained by this method are more reasonable, reflecting the differences between different configurations, subsystems, and components.