文章结合当前电力光纤通信网的建设情况以及光纤网络技术的发展，阐述了基于同步数字体系(SDH)的网络主要的保护恢复方法及应用，网络互连时可采用的保护方式，并针对多层网络协同工作的问题，对基于SDH的多层网络生存性协调进行探讨，为网络拓扑的实际应用和网络结构的优化提供参考。

In connection with the current construction of electric power fiber-optic communication networks and the development of fiber-optic network technologies, this paper explains the main protection and restoration techniques and applications of SDH networks and the protection modes that can be applied in network interconnection. In view of the coordination of multi-layer networks, it explores the survivability coordination of SDH-based multi-layer networks, providing a useful reference for the practical applications of network topology and the optimization of network structure.