故障定位对于波分复用 ( WDM)全光网络的保护非常重要 .文章给出了一种简洁有效的基于因果链和集合论的故障定位方法 ,并详细分析了故障模型 ,证明了用于故障定位的公式 ,进行了算法的时间和空间复杂性分析 ,还给出了实际设备的告警和故障的详细描述 Fault locating is very important for the protection of all optical networks in wavelength division multiplexing (WDM) .This paper presents a concise and effective fault location method based on causal chain and set theory, analyzes the fault model in detail, Positioning of the algorithm, the algorithm carried out time and space complexity analysis, but also gives a detailed description of the actual equipment alarm and fault