由于同时存在备用应力和需求应力，导致了备用设备可靠性模型的多样化。本文首先分析了备用失效模型和需求失效模型的特点；然后，对同时考虑两种应力的综合模型的表达形式和适用性进行了分析，并提出上述三个模型的基本使用原则；最后，针对目前核电厂可靠性数据的积累现状，对模型参数的评估方法进行了研究，提出三个不同层次数据的评估方法，并在此基础上给出了我国核电厂备用设备可靠性模型和参数评估方法的使用建议。

Because the standby equipment is affected by demand stress and standby stress simultaneously, its reliability model is diverse. Firstly, the characteristics of two essential models—standby failure model and demand failure model is analyzed; And then, the expression and applicability is presented, and the fundamental using principles are provided; Next, the evaluating methods of the model parameters is researched, after that three methods corresponding to the generic database and special data are advanced. Finally, the using advice of the model and its evaluating methods in domestic nuclear power plants are proposed.