Embodiments of this application provide a method for detecting a connection relationship in a radio frequency channel in a base station antenna and calibrating a channel, including: receiving a sample from a calibration network, where the sample is a signal obtained by adding a phase identifier to a coupled signal of a radio frequency channel in a base station antenna through the calibration network, and the phase identifier is a phase value used to mark an antenna port connected to a radio remote unit RRU port on the radio frequency channel; and learning of, based on the phase identifier, an antenna port that is actually connected to the RRU port. In technical solutions provided in embodiments of this application, no component needs to be added, and no product size needs to be increased.