This application provides a method for transmitting data on a ring network. The ring network includes two adjacent FlexE cross-connection rings, each FlexE cross-connection ring includes at least three nodes, the two FlexE cross-connection rings have at least one common node, the common node carries a cross-ring end-to-end working path, and each of the two FlexE cross-connection rings includes one ring-shaped protection path. Because there is a protection path between any two adjacent nodes in the two FlexE cross-connection rings, if a link fault occurs in the common node, a node adjacent to the common node may transmit data from one FlexE cross-connection ring to another FlexE cross-connection ring by using the ring-shaped protection path. Therefore, reliability of the ring network including the at least two FlexE cross-connection rings is improved.