The present disclosure provides an uplink channel transmission method, a user equipment (UE), and a base station in the communications field. The method includes: determining, by the UE, n first channels and m second channels; allocating transmit power to L uplink channels according to a maximum uplink transmission time difference between the n first channels and the m second channels, where the L uplink channels include at least k second channels among the m second channels; and transmitting the L uplink channels. The first channel is an uplink channel corresponding to a first cell on a first time unit numbered i, and the first time unit has a first transmission time interval (TTI). The second channel is an uplink channel corresponding to a second cell on a second time unit numbered j, and the second time unit has a second TTI. The second TTI is shorter than the first TTI.