The embodiments of this disclosure disclose an array antenna system. The array antenna system includes M antenna radiation units, a strip line feed system, a strip line ground plane, and a strip line cavity; the strip line feed system includes a phase shift circuit and N first printed circuit boards PCBs configured to implement a power allocation function and/or a phase compensation function; the phase shift circuit is located in the strip line cavity, P first PCBs are located on an outer surface of the strip line cavity; all or some of the M antenna radiation units are connected to signal planes of the N first PCBs, and the signal planes of the N first PCBs are in a radio frequency connection to the phase shift circuit by using probes; and ground planes of the N first PCBs are in a radio frequency connection to the strip line ground plane.