The disclosure discloses a method for transmitting uplink control information. The method includes: receiving, by a user equipment, a carrier activation command or a carrier deactivation command in a downlink subframe n; updating a first downlink activated carrier set according to the received carrier activation command or the carrier deactivation command into a second downlink activated carrier set; taking the second downlink activated carrier set as a current downlink activated carrier set corresponding to a first uplink subframe which belongs to a subframe set of an uplink subframe n+k and uplink subframe(s) after the uplink subframe n+k; sorting X piece(s) of Uplink Control Information (UCI) corresponding to X downlink carrier(s) according to a sorting rule, and transmitting the sorted X pieces of UCI to a base station in the first uplink subframe.