A method and an apparatus for aligning antenna beams in a high-low frequency co-site network, where the method includes performing antenna alignment of a low frequency beam with a communications device in order to establish a low frequency channel, and performing high frequency beam alignment of a high frequency antenna with the communications device using the low frequency channel. In the method, high frequency beam alignment of a high frequency antenna is performed using an established low frequency channel. Therefore, a technical problem that a high frequency beam alignment time of a high frequency antenna is long due to a narrow field of view of a high frequency beam can be avoided in order to quickly implement high frequency beam alignment of a high frequency antenna.