An overhead processing technology in an optical network and an overheads processing method, including: generating, by a network device, an optical supervisory channel (OSC) frame, where the OSC frame includes a plurality of overhead code block units, each of the plurality of overhead code block units bears an overhead of one type, the OSC frame carries overhead identification information, the overhead identification information is used to identify overhead types of overheads born by the plurality of overhead code block units, and overheads include an optical transmission section overhead, an optical multiplex section overhead, and an optical tributary signal assembly overhead; and sending, by the network device, the OSC frame.