With the research and application of new monitoring technology in smart substation represented by the Cluster Measurement and Control System (CMCS), it is urgent to develop a centralized mode of operation and maintenance matching to match the new architecture. It should focus on meeting the needs of centralized monitoring, efficient maintenance and security management. On the basis of the new equipment form of CMCS, a new operation and maintenance management system and platform based on centralized operation and maintenance idea has been successfully developed. The function design, architecture design and key implementation technologies of the centralized platform are systematically expounded. The developed platform enhances the ability of mal-operation proof between bays through advanced communication technology and security measures and provides effective support for realizing panoramic and visual operation and maintenance of CMCS. The practical application shows that the proposed centralized operation and maintenance system and platform fully meet the new requirements of the new monitoring system for smart substation, and lay a solid foundation for the promotion of the new monitoring system. This work is supported by Science and Technology Project of State Grid Corporation of China (No. 5206001601YU) “New System Architecture of Intelligent Substation Monitoring System and Key Technology Research and Application”.