The material characteristics of silicon carbide substrate， which are difficult to machine， coupled with its amplification effect of large-sized and ultra-thinned， pose a huge challenge to existing processing technologies. Consequently， the processing technology of high efficiency and high quality for silicon carbide substrate has become a current research focus. In this paper， the research progress of mechanical and chemical grinding and polishing technology for silicon carbide substrates is reviewed. The characteristics of various grinding and polishing technologies are compared. The challenge and development trend of grinding and polishing technologies of silicon carbide substrate is pointed out to provide new ideas and methods for high quality， high efficiency， and low-cost processing of large-size silicon carbide substrate.