In order to solve the problem of substation automation system which contains multi types and is distributed widely and maintained difficultly, this paper designs and implements a service management center for substation maintenance. The architecture of the wide area operation and maintenance service management center is designed based on the existing network structure which contains substation, main station and overhaul. This architecture proposes a whole process control of service which contains service registration, application, monitoring and so on, using simple service description language and general service protocol as service management standardization interaction. Security mechanism such as safety certificate, authority, and responsibility area is used to implement the display, monitoring and management of the substation automation system in wide area. The service management center for substation wide operation and maintenance has been used in Jiangsu provincial dispatch center, and Nanjing and Suzhou local dispatch center. This work is supported by Science and Technology Project of State Grid Corporation of China “Research and Application of Wide-area Operation and Maintenance Techniques of Substation Automation Equipment”.