Downlink control information transmission method and device, and communication system

A downlink control information transmission method and device, and a communication system. The transmission method comprises: a base station sending downlink control information for multiple user superposition transmission, wherein the downlink control information comprises control information about a first user equipment and control information about a second user equipment for performing multiple user superposition transmission with the first user equipment. Thus, the influence of a user equipment on a DCI decoding behaviour in an existing system can be avoided as far as possible, and the signalling complexity is not increased.