Through the experiments on cutting SiC wafer under the workpiece rotating,the surface microtopography ofslices was analyzed. The affecting laws including saw wire speed,workpiece feed speed and workpiece rotational speed onsurface roughness and tangential force of slice were studied. The results show that the wafer surface is flat and smooth andthere are no obvious bumps or grooves along the sawing direction due to additional rotation of the workpiece in this experiment condition. The surface roughness of slice reduces from Ra 1.532 m to Ra 0.513 m when the speed increases from 0r/ min to 12 r/ min. Thus the quality of slice surface is improved. The value of surface roughness and tangential force reduce when wire saw speed and workpiece rotation speed increase and workpiece feed speed decreases. However, the value of surface roughness and tangential force will increase when wire saw speed and workpiece rotation speed excessively increase.