Cabled seafloor observatories play an important role in ocean exploration for its long-term,real-time,and in-situ observation characteristics.In establishing a permanent,reliable,and robust seafloor observatory,a highly reliable cable switching and fault isolation method is essential.After reviewing the advantages and disadvantages of existing switching methods,we propose a novel active switching method for network configuration.Without additional communication path requirements,the switching method provides a way to communicate with a shore station through an existing power transmission path.A coded voltage signal with a distinct sequence is employed as the communication medium to transmit commands.The analysis of the maximum bit frequency of the voltage signals guarantees the accuracy of command recognition.A prototype based on the switching method is built and tested in a laboratory environment,which validated the functionality and reliability of the method.