A method for controlling activation of a bandwidth part (BWP), a user equipment, and a base station are provided. The method includes: receiving BWP configuration information transmitted by a base station; wherein the BWP configuration information is used to indicate a default BWP corresponding to each component carrier. After receiving the BWP configuration information transmitted by the base station, the method further comprises: receiving a component carrier activation signaling transmitted by the base station; and activating, based on the component carrier activation signaling, a first target component carrier and a default BWP corresponding to the first target component carrier.