A beam adjustment apparatus for an array antenna, wherein the array antenna comprises N receive array elements, and the adjustment apparatus comprises a receive weight adjuster, a combiner, an analog-to-digital conversion and baseband processor, N anti-aliasing filters, N low-rate analog-to-digital converters, a spatial filter, a signal optimizer, and a receive weight decision device, wherein the receive weight adjuster is configured to receive N received signals from the N receive array elements, and perform receive weight adjustment on the N received signals according to a receive weight adjustment coefficient, to obtain N received signals after the receive weight adjustment; the combiner is configured to receive the N received signals obtained after the receive weight adjustment, and combine the N received signals obtained after the receive weight adjustment, to obtain a combined received signal; the analog-to-digital conversion and baseband processor is configured to receive the combined received signal, and perform analog-to-digital conversion and baseband processing on the combined received signal: characterized in that the N anti-aliasing filters are configured to separately receive one signal that is coupled from each of the N received signals obtained after the receive weight adjustment, and separately perform anti-aliasing processing on the N coupled signals, to obtain N signals after the anti-aliasing processing; the N low-rate analog-to-digital converters are configured to separately receive the N signals obtained after the anti-aliasing processing, and separately perform low-rate analog-to-digital conversion, to obtain N digital signals; the spatial filter is configured to receive the N digital signals, and perform spatial filtering on the N digital signals according to a spatial filtering coefficient, to obtain N signals after the spatial filtering; the signal optimizer is configured to receive the N signals obtained after the spatial filtering, obtain an adjustment coefficient of the spatial filtering coefficient according to the N signals obtained after the spatial filtering, and send the adjustment coefficient of the spatial filtering coefficient to the spatial filter; and the receive weight decision device is configured to receive the spatial filtering coefficient, determine the receive weight adjustment coefficient according to the spatial filtering coefficient, and send the receive weight adjustment coefficient to the receive weight adjuster. characterized in that the N anti-aliasing filters are configured to separately receive one signal that is coupled from each of the N received signals obtained after the receive weight adjustment, and separately perform anti-aliasing processing on the N coupled signals, to obtain N signals after the anti-aliasing processing; the N low-rate analog-to-digital converters are configured to separately receive the N signals obtained after the anti-aliasing processing, and separately perform low-rate analog-to-digital conversion, to obtain N digital signals; the spatial filter is configured to receive the N digital signals, and perform spatial filtering on the N digital signals according to a spatial filtering coefficient, to obtain N signals after the spatial filtering; the signal optimizer is configured to receive the N signals obtained after the spatial filtering, obtain an adjustment coefficient of the spatial filtering coefficient according to the N signals obtained after the spatial filtering, and send the adjustment coefficient of the spatial filtering coefficient to the spatial filter; and the receive weight decision device is configured to receive the spatial filtering coefficient, determine the receive weight adjustment coefficient according to the spatial filtering coefficient, and send the receive weight adjustment coefficient to the receive weight adjuster.