Abstract: With the increasing maturity of multiplexing channel technology,line protection devices with voltage levels of 220 kV and above begin to adopt the optical multiplexing channel mode,which has obvious advantages in high optical fiber utilization rate,long communication distance,and reduced channel switching link. However,there is a problem that the protection optical transmission rate of the optical multiplexing channel does not match that of the optical terminal,and different manufacturers need different ways of handling. In this paper,the differences of the multiplexing channels of six mainstream protection manufacturers are analyzed,and the corresponding solutions are summarized.