Cover plate and device for chamfering circular sapphire wafer

The utility model discloses a cover plate for chamfering a circular sapphire wafer, which comprises a cover plate body consisting of an umbrella handle and an umbrella cover, and a cover plate cavity formed in the cover plate body, and the cover plate can be conveniently taken and placed from a product by an employee through the umbrella handle in the chamfering process; product convex face holes of the sapphire wafer to be machined are covered with the umbrella cover, and the situation that the copper air suction clamp leaks air, and products fall off is avoided. Vacuum is generated between the product and the copper air suction clamp through the cover plate cavity, so that a pressure difference is formed, and the product is sucked; therefore, the cover plate can seal a product hole, prevent air leakage of the copper air suction clamp, and prevent a product from falling off; a traditional method for pasting a protective film is replaced with the cover piece for processing, repeated utilization of a pasting c