A method and device for a discovery operation of User Equipment (UE) in a wireless communication system are provided. The method in which a network node supports a discovery operation of a UE includes: receiving, by a network node within a Home Public Land Mobile Network (HPLMN) of the UE, a Discovery Request message from the UE, wherein the Discovery Request message includes a candidate frequency list including an available plurality of carrier frequencies for announcing by the UE and an announcing PLMN ID including a PLMN Identifier (ID) of each of the carrier frequencies included in the candidate frequency list; and transmitting, by the network node within the HPLMN, a Discovery Response message to the UE, wherein the Discovery Response message includes carrier frequency information that indicates a carrier frequency selected for announcing by the UE among the carrier frequencies included in the candidate frequency list.