Abstract: In recent years, with the rapid development of the energy Internet, the business systems of State Grid Corporation of China have more and more requirements for the transmission bandwidth of the communication system. The single wave 10 G large capacity optical transport network (OTN) has been unable to meet the bandwidth requirements of data services and large particle services. At present, the technology of single wave 100 G OTN system is becoming increasingly mature, but there is a lack of research and analysis on the application of large-span 100 G OTN. This paper introduces the problem of OTN wave numbers that are difficult to open and meet business needs in the 385 km large-span 100 G OTN transmission design of Xinjiang A and B stations. Through experimental testing and data analysis, relevant conclusions and solutions have been drawn, which have important reference value for the future application of large capacity backbone optical transmission systems of State Grid Corporation of China.