An embodiment of the disclosure may provide a method performed by a master node (MN) in a wireless communication system, the method including: receiving, from a source-secondary node (S-SN), a first message including a conditional handover indicator, a conditional handover candidate cell list, a condition for each candidate cell, source cell group configuration information generated by the S-SN, and target cell group configuration information generated by the S-SN; transmitting, based on the first message and to a first target-secondary node (T-SN), a second message including the target cell group information; receiving, from the first T-SN, a third message including the target cell group information updated by the first T-SN; and transmitting, to a terminal, an MN radio resource control (RRC) reconfiguration message including an S-SN RRC reconfiguration message, wherein the S-SN RRC message further includes the source cell group configuration information generated by the S-SN and the target cell group information updated by the first T-SN.