A control information transmission method, a base station, and user equipment are disclosed. The transmission method includes: sending, by a base station, first control information on a second carrier, where the first control information is used by the base station to send data on a first carrier according to the first control information; and sending, by the base station, the data on the first carrier according to the first control information; where duration of a transmission time interval of the first carrier is less than duration of a transmission time interval of the second carrier.