The surface morphology and quality of 150 mm SiC wafers cut by multi-wire diamond wire saw was analyzed. The surface roughness Ra of C-plane was about twice of the Si-plane by testing the surface roughness of both sides of SiC wafers, respectively. The Si-plane of wafer cut by lateral abrasive particles of multi-wire diamond wire saw was smoother with more grinding effect applied to this plane because of the wafer bending towards to the Si-plane. In addition, the damage layer depth on both sides of SiC wafer was measured by the bonded interface sectioning technique. The results show that the damage layer depth of the Si-plane is about 789 μm, significantly lower than 138 μm of the C-plane. Observed by microscope, the cross-section of Si-plane edge wafer is smoother. It is further proved that the grinding effect of lateral abrasive particles on the Si-plane is stronger due to the wafer bending, resulting in differences in surface morphology and quality on both sides of the SiC wafer.