A dual damper device of a vehicle air vent includes a duct housing having a partition wall for dividing an air path, an introduction part and a discharge part, which are bent to be inclined; a pair of dampers rotationally mounted on the air path in the introduction part; a dial knob rotationally provided to the discharge part; a dial bush having a knob fitting part and an elongated guide groove; a pair of damper bushes vertically coupled to the dampers; and a bush link. The duct housing further includes a dial support member rotationally coupled to the dial knob and damper holding stepped protrusions provided to the partition wall and the introduction part.