本文对“基于知识的旋转机械故障诊断系统”中事例库的管理与维护进行了研究.提出了以不确定性知识来表达事例、利用事例的相似度进行事例的匹配及事例学习的方法,为基于事例的推理及事例库的管理与维护提供了良好的保证. This paper studies the management and maintenance of the case base in the knowledge-based rotary machinery fault diagnosis system, and puts forward the method of how to express the case by the knowledge of uncertainty and how to use the similarity of the case to match cases and case studies , Which provides a good guarantee for the management and maintenance of case-based reasoning and case base.