A user equipment and a circuit-switched fallback method thereof are provided. An initial base station sends a radio resource control connection release message containing the redirection frequency list to the UE. The redirection frequency list includes at least one redirection frequency. The UE determines a priority of the at least one redirection frequency according to a current registered LAI, a learning database and a piece of signal reference information of the redirection frequency list. Accordingly, the UE executes a circuit switch fallback procedure according to the priority of the at least one redirection frequency.