The research background and significance of remote operation and maintenance system for hydropower unit are expounded in this article. By introducing the idea of Industry 4.0 into the sector of control equipment manufacturing for hydropower unit, “Internet Plus” devices are applied to the control equipment of hydropower unit. P2P data exchange is established using NAT penetration technology to solve the decomposition/assembly and encryption problems of data flow under the UDP protocol. On this basis, the field devices can transparently and directly connected to the server, and the reinvestment of customer is reduced. A remote operation and maintenance system for control equipment of hydropower unit is developed in this article. This system could implement the remote monitoring, diagnosis, operation, maintenance, training, and technological service for the control equipment of hydropower unit, hence is worthy of promotion.