Apparatus and method for uplink transmission in wireless communication system

The disclosure relates to a fifth-generation (5G) or a pre-5G communication system for supporting a higher data transfer rate than a fourth-generation (4G) communication system such as Long-Term Evolution (LTE). The disclosure relates to uplink transmission in a wireless communication system, in which an operating method of a user equipment (UE) may include: receiving information about a UE group to which the same uplink resource is allocated from a base station; receiving uplink resource allocation information corresponding to the UE group from the base station; performing channel access for uplink transmission on the basis of the received uplink resource allocation information; and transmitting uplink data to the base station after accessing a channel, wherein the channel access may be performed using a multilevel threshold value in a contention slot for the UE.