A method for managing capacity of a wireless communication network, applied to a base station with a multi-sector structure, wherein the base station manages multiple overlay networks covering same cell coverage areas, and the multiple overlay networks covering same cell coverage areas comprise an overlay network with a sector combining function, multiple groups of antennas corresponding to each overlay network with a sector combining function are configured, and one power amplifier is configured for each antenna, the method comprising: checking total traffic of all the overlay networks managed by the base station; if the checked total traffic is smaller than a preset load threshold, searching for the overlay network with a sector combining function among all the overlay networks belonging to the base station; if there is only one overlay network belonging to the overlay network with a sector combining function, determining the overlay network as a first overlay network; if there are multiple overlay networks with a sector combining function, determining the first overlay network according to traffic, working frequency point information or a continuous coverage situation of the multiple overlay networks with a sector combining function, wherein the first overlay network is an overlay network with a sector combining function which is managed by the base station and requires network capacity management; wherein the determining the first overlay network according to the traffic, working frequency point information or continuous coverage situation of the multiple overlay networks with a sector combining function specifically comprises: selecting an overlay network with a sector combining function among the overlay networks as the first overlay network, wherein the overlay network has lowest traffic or a largest difference between its working frequency point and working frequency point of other overlay networks, or cells of the overlay network that are covered by sectors corresponding to the configured antennas are spatially discontinuous; maintaining normal work of a power amplifier of at least one antenna in each group of antennas in the first overlay network, and turning off power amplifiers of one or more other antennas; and connecting the one or more other antennas to the power amplifier maintaining normal work in the groups in which the one or more other antennas are located so that sub-sectors corresponding to each group of antennas among the multiple groups of antennas are respectively combined into multiple large sectors. checking total traffic of all the overlay networks managed by the base station; if the checked total traffic is smaller than a preset load threshold, searching for the overlay network with a sector combining function among all the overlay networks belonging to the base station; if there is only one overlay network belonging to the overlay network with a sector combining function, determining the overlay network as a first overlay network; if there are multiple overlay networks with a sector combining function, determining the first overlay network according to traffic, working frequency point information or a continuous coverage situation of the multiple overlay networks with a sector combining function, wherein the first overlay network is an overlay network with a sector combining function which is managed by the base station and requires network capacity management; wherein the determining the first overlay network according to the traffic, working frequency point information or continuous coverage situation of the multiple overlay networks with a sector combining function specifically comprises: selecting an overlay network with a sector combining function among the overlay networks as the first overlay network, wherein the overlay network has lowest traffic or a largest difference between its working frequency point and working frequency point of other overlay networks, or cells of the overlay network that are covered by sectors corresponding to the configured antennas are spatially discontinuous; maintaining normal work of a power amplifier of at least one antenna in each group of antennas in the first overlay network, and turning off power amplifiers of one or more other antennas; and connecting the one or more other antennas to the power amplifier maintaining normal work in the groups in which the one or more other antennas are located so that sub-sectors corresponding to each group of antennas among the multiple groups of antennas are respectively combined into multiple large sectors.