A method and an apparatus for power control in a wireless communication system are provided. When long-term evolution (LTE) and a new radio access technology (NR) are combined by means of dual connectivity (DC), etc., dynamic resource sharing can be used. Specifically, a user equipment (UE) determines whether or not uplink (UL) transmission is performed at a specific time point in a first carrier having a first processing time. When it is determined that UL transmission is not performed at the specific time point in the first carrier, the UE determines power for UL transmission at the specific time point in a second carrier having a second processing time shorter than the first processing time, on the basis of guaranteed power for the first carrier.