Abstract: With the increasing maturity of automation equipment, the requirements for real-time data acquisition and monitoring in substations by power grid dispatching are escalating. The existing remote terminal units are far from meeting the needs of dispatching management models, making the renovation of remote terminal units imperative. Due to the high real-time requirements of the 104 telecontrol service in the dispatch data network, the switching and renovation of remote terminal units must be completed under the condition of ensuring uninterrupted real-time data at the station end. For this purpose, based on the 220kV Xiayuan Substation in Zhangjiakou, a multi-channel address switching method with a dual-network redundancy strategy is proposed. The risks and considerations during the switching and renovation process are analyzed, and the specific implementation steps for the switching and renovation are provided. Ultimately, each new remote terminal unit can achieve autonomous switching between the reception and forwarding of station-wide information from two old telecontrol devices, ensuring seamless connection of telecontrol real-time services and smooth transition of uploaded data. It exhibits good redundancy and high reliability, providing valuable insights for the remote terminal unit renovation of similar substations.