A multi-beam antenna array system according to an exemplary embodiment of the present disclosure includes: a grounding surface; a plurality of multi-beam antennas which each includes a dielectric substrate and a radiating part formed on the dielectric substrate so as to radiate electromagnetic waves, and is disposed above the grounding surface so as to be spaced apart from each other; and a feed circuit which is formed on a lower portion of the grounding surface, and supplies electric power to the plurality of multi-beam antennas so that the electromagnetic waves are radiated in different directions from the plurality of multi-beam antennas.