As the current main transmission equipment of the electric power communication network, MSTP (multi-service transport platform based on SDH) equipment is carrying the key data for remote monitoring and controlling power grid. SDH principle was used to achieve the interconnection and interworking of various communication services between different kinds of optical transmission equipment, the problem of distal independent element’s remote monitor and controlling in central station was solved through Ethernet channel, the basic transmission principle of SDH and the condition of interconnection and interworking were summarized, and the fusion of different optical transmission equipment networks was realized with the lowest cost. The safety level of power communication network was improved effectively.