A binding segment identifier processing method and a device are provided. The method includes a network device receives a message sent by a controller, where the message includes type information and a segment identifier, and the type information indicates that the segment identifier is a binding segment identifier BSID. The network device performs a processing action on the BSID based on the type information. According to embodiments of this application, the network device can identify the BSID, to resolve a technical problem that an incorrect processing result is caused when a segment identifier list of the network device includes the BSID.