How to improve the surface quality of large-scale silicon wafer in the ultra-precision grinding process, will always be the most important issue discussed by the silicon wafer manufacturer. In this paper, the advantage of ultrasonic grinding is being explored. These advantages included small macro grinding force, grinding stress, low grinding heat, which will reduce the surface damage. Combined with relatively abrasive, a large-scale silicon wafer can be processed. Through the study, an experimental system for ultrasonic grinding of large-scale silicon wafer is designed. The working parameter is optimized and the expected result is obtained, which searches a new way for the practical implementation.