In another embodiment of the present disclosure, in multiple scanning processes, the mobile terminal may perform high frequency beam alignment of a high frequency antenna without determining a scanning sector with a strongest signal using a power detection method. For example, the base station may send synchronization sequence information and a pilot. The mobile terminal determines whether the base station and the mobile terminal are synchronized, and obtains, according to a result of the determining, a serial number of a high-frequency narrow beam used for performing high frequency beam alignment of a high frequency antenna, to perform high frequency beam alignment of a high frequency antenna. If the mobile terminal obtains multiple synchronization sequences by means of parsing, high-frequency narrow beams corresponding to the multiple synchronization sequences are used as candidate high-frequency narrow beams required for alignment. The base station and the mobile terminal select an optimal high-frequency narrow beam from the candidate high-frequency narrow beams according to a priority, to perform high frequency beam alignment of a high frequency antenna. If obtaining only one synchronization sequence by means of parsing, the base station and the mobile terminal use a high-frequency narrow beam corresponding to the synchronization sequence as a high-frequency narrow beam used for alignment in order to perform high frequency beam alignment of a high frequency antenna. If the mobile terminal obtains no synchronization sequence by means of parsing, the base station and the mobile terminal cannot be synchronized.