A device for applying a coating on a component where the component includes an inner surface, an outer surface, and end surfaces. The coating device includes a supporting pedestal, a UV light-transparent cover plate, a first pumping device, and an injecting device. The supporting pedestal is configured for holding the inner surface of the component, the end surfaces and the outer surface are exposed in the forming cavity. A through hole is defined in the center of the pedestal and a forming cavity is defined between the cover plate and the component when the cover plate is placed and secured on the pedestal. The first pumping device applies suction to the through hole to hold the component on the pedestal and the injecting device injects UV light-curable coating material in liquid form into the forming cavity.