This application provides a wireless communication method, device, and system. The wireless communication 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 minKO 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 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 delay includes N time units. After the first time period since the terminal device receives the scheduling DCI, the terminal device has a capability of receiving the PDSCH or sending the PUSCH on the target BWP.