The invention discloses a glass substrate conveying device and a method for detecting rotation synchronism of driven shafts. The conveying device comprises a plurality of driven shafts, a plurality of rollers, a reflector plate and an infrared sensing unit, wherein the driven shafts are parallelly arranged at intervals along a first direction, and through holes penetrating through the driven shafts are formed in the first direction; the rollers are fixed on the driven shafts at intervals and used for bearing a glass substrate, and rotate along with the rotation of the driven shafts to drive the glass substrate to flow; the infrared sensing unit emits infrared rays, receives reflected lights of infrared rays which are emitted by the infrared sensing unit and reflected by a barrier, and judges the rotation synchronism of the driven shafts according to the strength value of the reflected lights; and the through holes and the reflector plate are positioned in the propagation direction of the infrared rays emitted by the infrared sensing unit. Therefore, by the method, whether the rotation of the driven shafts is synchronous or stopped can be detected in time, and the glass substrate is prevented from generating scratches or fragments.