Abstract: The switch stations of the first batch of commercial nuclear power plants in China adopted analog control technology and are now facing problems such as equipment aging and discontinued spare parts. To solve this problem, a digital transformation project of the switch station has been carried out in a nuclear power plant, upgrading the analog control system to network computer monitoring system and simultaneously transforming the telecontrol system. In view of the situation that the control system of the switch station of this project is transformed without overall power outage, transformation is performed through multiple rounds of scheduled maintenancev, the coexistence and operation of the old and new control systems for a long time, and in response to the different access requirements of the dispatching end, a remote control system transformation scheme without overall power outage is proposed. The implementation steps and risk control measures of the scheme are introduced.