Abstract: In response to the challenges posed by the rapid increase in substation automation equipment and the inefficiency of traditional on-site operation and maintenance modes, this paper researches and constructs a master station–substation coordinated remote operation and maintenance and centralized management system. By deploying an intelligent terminal on the substation side and building an integrated operation and maintenance platform on the master station side, a unified master–substation collaborative foundation is established. Based on this, a remote operation and maintenance system centered on "four remote functions (monitoring, inspection, control, and maintenance) and one centralized function (management)" is designed. This system achieves panoramic perception of equipment status, intelligent early warning, safe and efficient remote maintenance, and centralized management of distributed resources. The large-scale application in a provincial power grid demonstrates that the system effectively promotes the transformation of equipment operation and maintenance from on-site and decentralized to remote and centralized, significantly enhancing operational efficiency and proactive risk prevention capabilities.