Currently, dual communication power supply system has been widely used in different central stations and communication rooms of substations with different voltage levels in State Grid Corporation of China, but some of the loads are still in the single-channel power supply state. In order to avoid power service interruption caused by power cut of power supply load, the reliability of the dual-communication power supply system is further improved, and the traditional dual-communication power supply system and its existing problems are analyzed. On this basis, this paper designs an automatic bus coupler switch for dual communication power supply system, which takes the automatic bus coupler switch as the idea, the embedded monitoring protection as a means, and the control logic as a goal. In the case of power failure, the dual power supply system can switch seamlessly. Finally, simulation experiments show that the automatic bus-link switch operates stably, responds to faults instantaneously, sensitively and reliably, and can better meet actual needs. This work is supported by National Natural Science Foundation of China (No. 61403127) and Science and Technology Project of State Grid Corporation of China (No. 526800150054).