Large-size silicon carbide wafer polishing device and polishing method

The invention provides a large-size silicon carbide wafer polishing device and a polishing method.The polishing device comprises a polishing disc, a polishing pad arranged on the upper disc face of the polishing disc and a first driving shaft, a plurality of annularly-distributed ceramic discs are arranged above the polishing pad, and polishing gaps are formed between the ceramic discs and the polishing pad; a pressure disc is arranged above the ceramic disc, a second driving shaft is arranged on the pressure disc, a movable ring is arranged on the outer circumferential surface of the pressure disc in a sliding mode, a plurality of diamond finishing blocks which are annularly distributed at intervals are arranged below the movable ring, and a plurality of ceramic liquid uniformizing blocks are arranged between every two adjacent diamond finishing blocks. In the whole polishing process, the roughness of the surface of the polishing pad can be kept, the polishing removal rate is greatly increased, the pressure