The present specification suggests a method for transmitting an uplink channel in a wireless communication system and a device supporting same. More particularly, a method for transmitting, by a terminal, a physical uplink control channel (PUCCH) in a wireless communication system, comprises the steps of: receiving a physical uplink shared channel (PDSCH) from a base station; and transmitting, to the base station, the PUCCH including hybrid automatic retransmit request (HARQ)-acknowledgment (ACK) information for the PDSCH, wherein the PDSCH includes a first PDSCH and a second PDSCH, and the transmission power of the PUCCH is determined on the basis of a priority between the first PDSCH and the second PDSCH and/or a bit configuration of the HARQ-ACK information.