This application provides a beam management method, a terminal device, and a network device. The method includes: measuring, by a terminal device, a beam of a network device; and sending, by the terminal device, an identifier of a first beam to the network device, where the first beam is a beam on which a beam failure occurs or a beam meeting a first condition, and the identifier of the first beam is sent to the network device by using physical layer control signaling or by using MAC layer control signaling.