A base station handover method and system for a communication system are provided. The method includes: a serving base station triggering a bi-casting operation according to information reported by a user equipment, adding a communication context of a target base station into a Mobile Management Entity (MME), and the MME notifying a Serving GateWay (SGW) to store two communication routes; the SGW communicating with the serving base station and the target base station after the triggering of bi-casting is completed; and the serving base station interacting with the user equipment, and handing over the user equipment from the serving base station to the target base station. By means of the technical scheme according to the embodiments of the present document, the complexity of base station handover can be reduced, the efficiency of base station handover can be increased, and at the same time the practicability is enhanced.