A method by which a terminal transmits an uplink signal in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: determining whether transmission power of a plurality of uplink channels, which are simultaneously transmitted in a plurality of serving cells and has transmission time intervals (TTIs) of different lengths, exceeds maximum power of a terminal; and transmitting an uplink channel excluding an uplink channel, which is determined according to a preset priority rule, among the plurality of uplink channels when the transmission power of the plurality of uplink channels exceeds the maximum power of the terminal.