A ring network switching apparatus connects a plurality of communication nodes by a duplex ring type transmission line. Respective communication nodes autonomously vary respective connection state by respective transmission line switching means based on the control data received from the control data receiving unit. Respective communication nodes transmit the control information designating a new transmission line state from the control information transmission unit. Thereby, respective communication nodes autonomously recover its failure and perform a re-construction of a network without an aid of a parent station. Further, the transmission data from the communication node is outputted to both transmission lines through a hybrid output section. Thus, respective communication nodes merely observe the state of the transmission line on the receiving side and switch the receiving switching means based on the observation. Therefore, the connection state of respective communication nodes can autonomously change, thereby providing a re-construction of a network at a high speed and simplifying a control circuit thereof.