Embodiments of the present application relate to the field of communications, and in particular, to a control information sending method and receiving method, a sender and a receiver, which are used for sending DCIs corresponding to DCI types to the receiver, thereby improving simplicity of interference suppression performed by the receiver. In the embodiments of the present application, a sender flexibly and optionally sends a first class of DCIs and/or a second class of DCIs. On one hand, when a receiver performs interference suppression on received interference signals, parameters of interference signals comprised in DCIs corresponding to a type of a received second class of DCIs can be used for interference suppression, thereby improving simplicity of interference suppression performed by the receiver; and on the other hand, when the receiver does not perform interference suppression on the received interference signals, a sender can send DCIs corresponding to a type of a first class of DCIs, and the first class of DCIs does not comprise the parameters of an interference signals, thereby reducing load capacity of data transmission and further reducing data processing complexity of the receiver.