The embodiment of the invention discloses a method, a device and a system for controlling the information sending under a multi-carrier-frequency mode. The method is used for sending control information in a multi-carrier-frequency system and comprises the following steps: generating control information sent and transmitted on each carrier frequency according to a preset transmission format; and sending the control information on a control channel of one carrier frequency in the multi-carrier-frequency system. The device comprises a first control information generation module and a first sending module, wherein the first control information generation module is used for generating the control information of data transmitted on each carrier frequency, and the first sending module is used for sending the control information on the control channel of one carrier frequency. The system comprises first network equipment and first terminal equipment, wherein the first network equipment is used for generating control information of data transmitted on a plurality of carrier frequencies and sending the control information on the control channel of one carrier frequency, and the first terminal equipment is used for monitoring and acquiring the control information. The embodiment of the invention can reduce the expense for dispatching signaling of a carrier frequency system and lower thecomplexity of a terminal for monitoring and decoding.