The invention relates to a shunt-type omnidirectional antenna array of three frequency bands of GSM (Global System for Mobile Communications) 850 / DCS (Distributed Control System) / PCS (Personal Communication Service), belonging to the field of antenna designs. The antenna array is a three-frequency-band base station system used for supporting the GSM 850 (824-894MHz), the DCS (1,710-1,880MHz) and the PCS (1,850-1,990MHz) and has the advantages of miniaturization, omnidirectional coverage rate, low cost and high gain. The antenna array is characterized in that parallel feed networks are adoptedin parallel dual feed structures of both the front side and the back side of a printed circuit board, and the adopted parallel feed network can ensure all antenna array elements are excited in the same direction on the premise of no any phase shift, thereby the problem that a series-fed type array bandwidth is limited by the feed networks is solved. Meanwhile, a three-frequency-band omnidirectional array element is designed in a mode of chamfering a printed dipole, and a microstrip short-circuit line is connected to compensate the capacitive impedance of the DCS / PCS frequency bands, thus the high-gain omnidirectional base station antenna of three frequency bands of GSM 850 / DCS / PCS is realized. The antenna array has the advantages of compact structure, miniaturization, easy integration andflexible design and is suitable for the design of a miniature multi-frequency-band high-gain base station antenna of a GSM 850 / DCS / PCS system.