Intelligent substation “shared-port and shared-network" technology requires the communication network management could identify and classify service message automatically. The substation communication services are analyzed and the service management flows are combed, then an intelligent substation communication service automatic discovery method is proposed. The method defines the common service message format and uses terminal devices to analyze new service messages and extracts the characteristic information, then service discovery messages are formed. System reports those messages to network management system to complete the service automatic discovery process. The relay protection device’s topology and service automatic discovery process are studied. With software development of the network management system, SV/GOOSE service is taken as an example to realize the automatic discovery and configuration of the service, verifying the effectiveness of service automatic discovery method. The results show that, through automatic service discovery, network management system can reduce service configuration workload and facilitate the staff to conduct service management. This work is supported by Science and Technology Project of State Grid Corporation of China (No. SGZJ0000BGJS 1600324).