The present disclosure provides a method for performing uplink transmission in a wireless communication system and an apparatus therefor. Specifically, a method for transmitting an uplink data channel by a user equipment (UE) in a wireless communication may comprise the steps of: receiving configuration information related to the uplink data channel; receiving control information for scheduling transmission of the uplink data channel; and transmitting the uplink data channel on the basis of the control information. Here, the configuration information may include one or more configurations including at least one of i) a transmission unit and ii) a beam, which are related to the transmission of the uplink data channel. In addition, on the basis of the one or more configurations, the control information may include information indicating a transmission unit and a beam to be applied to the transmission of the uplink data channel.