Embodiments of this application disclose a BWP deactivation method, a device, and a system, to deactivate one or more BWPs in a plurality of active BWPs of a first device. The method includes: receiving, by the first device, signaling sent by a second device; and deactivating, by the first device, a BWP of the first device based on the signaling. Technical solutions provided in the embodiments of this application are applicable to BWP deactivation.