A synchronization method, comprising: receiving, by the first base station, a first network reference signal from the second base station on an idle resource of the first base station; obtaining, by the first base station, a signal propagation delay between the first base station and a second base station by: obtaining, by the first base station, location information of the first base station and location information of the second base station; and calculating, by the first base station, the signal propagation delay between the first base station and the second base station according to the location information of the first base station and the location information of the second base station; or receiving, by the first base station, the signal propagation delay sent by a synchronization control end; or obtaining, by the first base station, the signal propagation delay from the first network reference signal, wherein the signal propagation delay is included in the first network reference signal; obtaining, by the first base station, a synchronization reference time by subtracting the signal propagation delay from a receiving time of the first network reference signal; and performing, by the first base station, synchronization with the second base station according to the synchronization reference time. receiving, by the first base station, a first network reference signal from the second base station on an idle resource of the first base station; obtaining, by the first base station, a signal propagation delay between the first base station and a second base station by: obtaining, by the first base station, location information of the first base station and location information of the second base station; and calculating, by the first base station, the signal propagation delay between the first base station and the second base station according to the location information of the first base station and the location information of the second base station; or receiving, by the first base station, the signal propagation delay sent by a synchronization control end; or obtaining, by the first base station, the signal propagation delay from the first network reference signal, wherein the signal propagation delay is included in the first network reference signal; obtaining, by the first base station, a synchronization reference time by subtracting the signal propagation delay from a receiving time of the first network reference signal; and performing, by the first base station, synchronization with the second base station according to the synchronization reference time. obtaining, by the first base station, location information of the first base station and location information of the second base station; and calculating, by the first base station, the signal propagation delay between the first base station and the second base station according to the location information of the first base station and the location information of the second base station; or receiving, by the first base station, the signal propagation delay sent by a synchronization control end; or obtaining, by the first base station, the signal propagation delay from the first network reference signal, wherein the signal propagation delay is included in the first network reference signal; obtaining, by the first base station, a synchronization reference time by subtracting the signal propagation delay from a receiving time of the first network reference signal; and performing, by the first base station, synchronization with the second base station according to the synchronization reference time.