The AC/DC hybrid distribution network is large in scale and high in voltage level, and contains more sources and loads, and the degree of control is more complicated. Therefore, the disconnection of the line in the AC/DC hybrid distribution network, the AC/DC fault of the system, and the change of the operating state of the flexible DC device may cause the operating mode of the system to change. In this paper, the corresponding system operation mode is proposed for the typical hand-hand AC/DC hybrid distribution network. The operating mode of the flexible DC device, the switching conditions of the flexible DC device, and the switching strategy are studied. The influence of the hot standby operation on the distribution network is analyzed, and the seamless switching of the flexible DC device is realized.