Abstract: In this paper the basic content, background, significance, classify of the model, main diagnostic algorithm, the newest research achievement, and problems need to solve for the system-level fault diagnosis are expounded.

• 文摘:阐述了系统级故障诊断的基本内容、背景、意义、模型的分类，主要诊断方法，最新研究成果和尚待解决的问题.