Disclosed are a beam generation method and a base station, used to solve the problem in the prior art of an increase in the number of columns of antennas and a decrease in the quality of communicationbeams when the beams are expanded from 2T to 4T. With respect to the feature of being more sensitive to an antenna width during antenna platform deployment, in the present application, planar array antennas are stacked on top of each other to form two half planes, wherein elements are weighted on each half plane independently. A signal generated by a baseband may be mapped to the upper-half planar antenna array of the planar array antennas, or mapped to the lower-half planar antenna array of the planar array antennas, or mapped to both the upper-half planar antenna array of the planar array antennas and the lower-half planar antenna array of the planar array antennas to form beams, so that the number of logical channels to which a plurality of signals generated by the baseband may be mapped can be doubled. Accordingly, beams can be expanded without increasing the number of columns of antennas, e.g. expanded from 2T to 4T, and since the antenna width of the half plane is not reduced, the quality of communication beams is not affected.