A method for negotiating link capability information, wherein after a higher order optical channel data unit, ODU, link is established, the method comprises: receiving, by a second node, first higher order ODU link capability information supported by a first node at one end of the link, where the second node is located at the other end of the link, wherein the first higher order ODU link capability information comprises: a first lower order ODU type and a first tributary slot type which are supported by the first node when multiplexing is performed; determining, by the second node, link capability information according to the first higher order ODU link capability information and second higher order ODU link capability information that is supported by the second node, wherein the second higher order ODU link capability information comprises: a second lower order ODU type and a second tributary slot type which are supported by the second node when multiplexing is performed, the link capability information comprises: a lower order ODU type which is supported by the link when multiplexing is performed and a tributary slot type supported by the link, the determining the link capability information comprises: determining an intersection of the first lower order ODU type and the second lower order ODU type as a lower order ODU type which is supported by the link when multiplexing is performed; determining, when tributary slot granularity of the first tributary slot type is equal to tributary slot granularity of the second tributary slot type, any of the first tributary slot type and the second tributary slot type as a tributary slot type supported by the link, or when tributary slot granularity of the first tributary slot type is not equal to tributary slot granularity of the second tributary slot type, a tributary slot type with greater tributary slot granularity as a tributary slot type supported by the link; and sending, by the second node, the link capability information to the first node. receiving, by a second node, first higher order ODU link capability information supported by a first node at one end of the link, where the second node is located at the other end of the link, wherein the first higher order ODU link capability information comprises: a first lower order ODU type and a first tributary slot type which are supported by the first node when multiplexing is performed; determining, by the second node, link capability information according to the first higher order ODU link capability information and second higher order ODU link capability information that is supported by the second node, wherein the second higher order ODU link capability information comprises: a second lower order ODU type and a second tributary slot type which are supported by the second node when multiplexing is performed, the link capability information comprises: a lower order ODU type which is supported by the link when multiplexing is performed and a tributary slot type supported by the link, the determining the link capability information comprises: determining an intersection of the first lower order ODU type and the second lower order ODU type as a lower order ODU type which is supported by the link when multiplexing is performed; determining, when tributary slot granularity of the first tributary slot type is equal to tributary slot granularity of the second tributary slot type, any of the first tributary slot type and the second tributary slot type as a tributary slot type supported by the link, or when tributary slot granularity of the first tributary slot type is not equal to tributary slot granularity of the second tributary slot type, a tributary slot type with greater tributary slot granularity as a tributary slot type supported by the link; and sending, by the second node, the link capability information to the first node.