This paper induces the OTN technology from the analysis of provincial trunk wavelength division system, and introduces the core contents including the electric layer technology, optical layer technology, packaging operations, performance monitoring. It describes the basic elements of the OTN network planning. According to the technical characteristics and networking requirements, it draws up Shanxi Unicom trunk transmission network application program, and analyzes the network maintenance and maintenance personnel skill requirements in detailed. OTN technology will be widely used in provincial trunk transmission network.