This application provides a link failure detection method. A terminal device measures quality of radio links corresponding to reference signals in a set. When any one of the radio links is of poor quality, and not all of the radio links are of poor quality, the terminal device notifies a network device of the radio link of poor quality. After determining the radio link of poor quality, the network device does not send and/or receive communication data between the network device and the terminal device on the radio link of poor quality, or does not send and/or receive, on the radio link of poor quality, communication data that does not satisfy a service requirement.