Embodiments of the present disclosure provide a method and an apparatus for performing communication in software-defined networking, and a communications system. The method includes: receiving a message sent by a network device, where the message includes a signaling message; determining, according to a control policy, a matching condition that matches the message, where the control policy includes a matching condition and operation information corresponding to the matching condition; processing the message according to the operation information corresponding to the matching condition that matches the message; and sending the processed message to the network device. According to the method and the apparatus for performing communication in software-defined networking, and the communications system in the present disclosure, a problem in the prior art that a control device serving as a network control center cannot communicate with a base station is resolved.