The present disclosure provides a method by which a terminal, in which a primary cell and a secondary cell are set, activate a bandwidth part (BWP) in a wireless communication system, comprising: receiving downlink control information (DCI) from a network, the DCI notifying the terminal of the separation of the secondary cell from the dormant BWP; and activating a specific BWP of the secondary cell on the basis of the DCI, the specific BWP being a BWP set by upper layer signaling received through the terminal.