The disclosure relates to a channel access method and apparatus in a wireless communication system. In the method according to an embodiment of the disclosure, a user equipment (UE) may receive configuration information related to a beam used in an unlicensed spectrum and configuration information related to transmission of a synchronization signal block from a base station, determine a threshold value used for a channel access procedure based on the configuration information received from the base station, and transmit a signal through the unlicensed spectrum according to whether the unlicensed spectrum is in an idle state, determined based on the determined threshold value.