This application provides a communication method and a terminal device. The communication method may include determining, by user equipment (UE), a candidate resource set on a first carrier, where the first carrier is a carrier on which a resource is currently to be selected, and the first carrier is used to transmit first data. The method may also include selecting, by the UE, a resource on the first carrier from the candidate resource set based on a preset condition, where the preset condition is determined based on resources selected by the UE on other carriers and one or more of the following: a quantity of transmit chains of the UE, a transmit power of the UE, a quantity of resource blocks occupied by the UE, a frequency domain spacing between a plurality of carriers or a plurality of frequency domain resources occupied by the UE, a carrier switching time of the UE, and a half-duplex limitation to the UE, the other carriers indicate all carriers on which the UE has currently selected a resource, and the other carriers are used to transmit second data. The method may also include sending, by the UE, the first data on the resource selected on the first carrier.