The invention provides a wafer grinding method. The wafer grinding method includes the steps that a wafer is provided and comprises a functional face and a back face opposite to the functional face; after a protective layer is formed on the functional face of the wafer, the protective layer is covered with a layer of protective adhesive tape; then, the wafer is placed on a grinding device, the back face of the wafer is ground so that the portion, with the partial thickness, of the wafer can be removed; and the protective adhesive tape is removed, and then the protective layer is removed. Before grinding, the protective layer is formed on the functional face of the wafer, and then the protective layer is covered with one layer of protective adhesive tape. In the grinding process of the protective adhesive tape, the structure on the functional face of the wafer can be effectively protected against damage in the grinding process, the protective adhesive tape is pasted on the protective layer, the situation that the protective adhesive tape makes contact with the functional face of the wafer can be effectively avoided, and therefore in the process of tearing off the adhesive tape after the grinding technology, the protective adhesive tape can remove defects of parts on the surface of the functional face of the part of the wafer, and structural damage on the functional face of the wafer is reduced.