Embodiments of the present disclosure provide a method for controlling power of an uplink channel, a UE and a communication system. The method for controlling power includes: a UE sorts priorities of uplink channels of at least two cells, when transmitting signals of the uplink channels containing uplink control information for the at least two cells within the same subframe; and allocates power for the uplink channels of the at least two cells according to a result of priority sorting; when allocating power for an uplink channel, needed power of one or more uplink channels with lower priorities than that of the uplink channel is taken into account. With the embodiments of the present disclosure, not only power may be allocated for uplink channels of high priorities, but also uplink channels of low priorities may be transmitted punctually, thereby further improving overall performance of uplink information transmission.