针对大型液体火箭推进系统故障诊断工作的需要， 建立了一种推进系统故障诊断反问题模型，并提出了基于遗传算法的反问题求解算法．在对故障诊断反问题的特点与困难及其求解方法研究的基础上，重点论述了基于遗传算法的反问题求解算法和基本过程．最后，给出了液体火箭推进系统故障诊断反问题求解的具体例子，表明所建立的推进系统故障诊断反问题模型及所提出的算法是合理有效的． In order to meet the need of fault diagnosis of large liquid propellant rocket propulsion system, an inverse problem model of propulsion system fault diagnosis is established, and an inverse problem solving algorithm based on genetic algorithm is proposed. On the basis of the research on the characteristics and difficulties of the inverse problem of fault diagnosis and its solving methods, this paper focuses on the algorithm and basic process of solving inverse problem based on genetic algorithm. Finally, a concrete example of solving the inverse problem of the liquid propellant rocket propulsion system is given, which shows that the inverse problem model of the propulsion system and the proposed algorithm are reasonable and effective.