针对传统的民航飞机故障诊断规则来源于适航审定的标准文件,不能满足改善诊断效率的要求,在建立民航飞机故障诊断的知识复合模型的基础上,从可靠性报告中提取原始数据,进而基于粗糙集对这些数据进行预处理和约简,获取新的诊断规则,有效地提高了故障诊断的效率.实例推导出新的诊断规则,实现了传统的故障诊断规则的改进,说明了方法的可行性. In view of the traditional civil aircraft fault diagnosis rules come from airworthiness certification standard documents, can not meet the requirements of improving the diagnostic efficiency, based on the establishment of a knowledge complex model of civil aviation aircraft fault diagnosis, extract the original data from the reliability report, and then based on Rough set of these data pretreatment and reduction, access to new diagnostic rules, effectively improve the efficiency of fault diagnosis.Examples derived new diagnostic rules, to achieve the improvement of the traditional fault diagnosis rules, illustrates the feasibility of the method .