An active array antenna module includes a cover plate, a metal frame, an antenna main board, a back frame, and a plurality of first fixing structures. The first fixing structures fix the back frame, the metal frame, and the cover plate, so that the antenna main board is fixed between the metal frame and the back frame, so that each of a plurality of antenna units of the antenna main board corresponds to each of a plurality of openings defined by the metal frame and each of a plurality of metal patterns of the cover plate to form a cavity antenna unit, and the active array antenna module includes a plurality of the cavity antenna units.