A lens barrel coating aid apparatus includes a holder, a suction component and a suction source. The holder includes a holding surface, securing portions positioned on the holding surface to fix lens barrels, and a first positioning portion. The first positioning portions are formed on the holding surface, and spaced from the securing portions. The suction component includes a suction surface facing the holding surface and a second positioning portion corresponding to the first positioning portion. Suction holes are defined on the suction surface corresponding to the securing portions. The suction holes are configured to suck plugs to insert into or pull out of the lens barrels. The second positioning portions are formed on the suction surface, and spaced from the suction holes. The suction source is connected with the suction holes, and provides suction force to the suction holes.