The present disclosure relates to a method by which a terminal aligns uplink synchronization in a wireless communication system. The method comprises the step of acquiring a difference value between synchronization signal (SS)/physical broadcast channel (PBCH) block-based first downlink synchronization corresponding to a first beam and SS/PBCH block-based second downlink synchronization corresponding to a second beam. The method comprises the step of transmitting, to a base station, report information including information associated with the difference value, on the basis of the comparison of the second downlink synchronization and cyclic prefix (CP) length. The method comprises the step of receiving, from the base station, information about a timing advance (TA) value derived on the basis of the information associated with the difference value.