A guard band indication method on an unlicensed spectrum is described that includes: a network device generating one or any combination of the following four types of information on the unlicensed spectrum: an indication of bandwidth configuration information, an indication of available bandwidth information, an indication of unavailable bandwidth information, or an indication of guard band information; and the network device sends the one or any combination of the foregoing four types of generated information. The one or any combination of the four types of information is used to determine a guard band that is based on a listen before talk (LBT) result.