Abstract: With the continuous development of electric power information technology, the construction of large capacity, high bandwidth OTN network by electric power enterprises has become a trend. According to the Guangdong power OTN network's engineering characteristics, this papar gives an analysis on network structure, cross technology, network protection, and it selects a three-layer structure including the core layer, backbone layer and access layer, the backbone layer uses OPGW to build MESH network based on power grid structures. There are no less than 2 connections between backbone layer and core layer, the same to backbone layer and access layer, which improves the network reliability besides controling the investment. This paper also gives the technology choice of the cross technology and the network protection, giving reference to OTN network construction by electric power enterprises. At the end, this paper gives an application case using OTN idle channels to provide emergency support for Guangdong power grid, which in the typhoon prone area.