Embodiments of this application provide a wireless communication method, device, and system. The method includes: A terminal device receives first information from a network device, where the terminal device currently uses a first BWP, and the first information indicates that in minK0 time units after the terminal device receives scheduling downlink control information (DCI), there is no downlink shared channel (PDSCH) scheduled by the scheduling DCI, and/or in minK2 time units after the terminal device receives the DCI, there is no physical uplink shared channel (PUSCH) scheduled by the scheduling DCI; the terminal device receives the scheduling DCI from the network device, where the scheduling DCI indicates the terminal device to switch from the first BWP to a target BWP; and the terminal device determines a first time period based on a bandwidth part (BWP) switch delay and the first information, where the BWP switch delay includes N time units.