The excellent chemical and mechanical properties of SiC single crystal make damage free surface preparation for SiC wafers a great challenge.Double side lapping, mechanical polishing and chemical mechanical polishing are traditionally utilized for SiC wafer preparation.However, double side lapping produce an acceptable flat surface but introduce significant subsurface damage.Mechanical polishing is limited by the difficulty of obtain a surface with sufficient low damage layer.In this paper, nanogrinding of SiC wafers with fine diamond wheels were proposed.Experimental results showed that nanogrinding could produce a flatness of less than 1.0 m and a surface roughness of 0.42 nm Ra for 2 inch SiC wafers.It was found that nanogrinding was capable of producing much flatter SiC wafers with lower damage than double side lapping and mechanical polishing in far less time and it could replace double side lapping and mechanical polishing and reduce the removal amount for chemical mechanical polishing.These results provide useful information for preparing high quality SiC wafers with high efficiency and low cost.