Method, device and system for adjusting coverage area of base station

The invention provides a method, a device and a system for adjusting the coverage area of a base station. The method for adjusting the coverage area of the base station comprises the following steps of: acquiring a throughput rate of a sector; if the throughput rate of the sector is more than or equal to a heavy load threshold, acquiring a step value for adjusting downtilt or a transmitting power of an antenna of the sector according to signal quality data which is reported to the sector when a terminal switches the base state or according to a pre-stored reference data table; sending a first adjustment command which carries the step value to the base station to which the sector belongs, so that the base station can adjust the downtilt or the transmitting power of the antenna of the sector according to the step value after receiving the first adjustment command, and the coverage area of the base station is adjusted. By the method, the device and the system, the size of a coverage overlapping area of the base station and an adjacent base station is guaranteed, so that terminals which are positioned in the coverage overlapping area can enjoy normal voice service and data service, the phenomenon of unsuccessful switching or ping-pong switching is avoided, and the communication quality of the terminals in the coverage overlapping area is improved.