Embodiments of the present invention disclose a primary secondary cell change method and a base station. The primary secondary cell change method in the embodiments of the present invention includes: determining, by a primary base station, to change a first primary secondary cell served by a secondary base station, and selecting a second primary secondary cell from cells served by the secondary base station; sending, by the primary base station, a first message to the secondary base station, which is used to request the secondary base station to change the primary secondary cell, where the first message includes an identity of the second primary secondary cell; and sending, by the primary base station, a second message to a user equipment UE, which is used to request the UE to use the second primary secondary cell.