The invention discloses a device for realizing synchronization of a mobile communication micro-base station or an indoor base station, characterized in that, information of an air cell is extracted in a mobile communication micro-base station or an indoor base station by a synchronization unit device composed of a physical layer signal processing unit, a signal processing unit, a radiofrequency processing unit, a source generator unit, a synchronization decision unit and an antenna, thereby realizing the object of air interface synchronization and carrier wave synchronization of the base station with the whole system. Accordingly, planning difficulty of whole system frequency spectrum can be decreased, system interference is reduced, and project mounting/debugging workload is decreased. With the method and device, the base station is capable of operating in any situation, such as a situation that a base station mounting region is covered by singles, and a situation that the region is not covered by signals. The principle disclosed in the invention can be used in other 3G mobile communication systems so as to overcome the faults in setting synchronization point and frequency by a 3G mobile communication base station.