Silicon carbide （SiC） is widely used in infrared optics and semiconductor manufacturing. Investigating the grinding and polishing behavior of hard and brittle silicon carbide at the nanoscale is of great significance for improving component performance. In this study， a molecular dynamics model of 6H-SiC tumbling polishing was established to investigate the influence of different rolling speeds of diamond abrasive grains on the material removal behavior， surface morphology， subsurface damage， tangential and normal forces， and friction coefficient of the 6H-SiC workpiece， thereby revealing the damage mechanism of 6H-SiC during grinding and polishing. The results indicate that at a rolling speed of 25 m/s， chips accumulate in front of the abrasive grain due to shear and extrusion. As the rolling speed increases， the chips adhere to the abrasive grain and eventually detach， resulting in no chip accumulation on the workpiece surface. With an increase in the abrasive grain’s rolling speed， the material removal mechanism of 6H-SiC gradually shifts from being predominantly plowing-driven to adhesion-driven. Consequently， the subsurface damage depth， average atomic temperature， tangential force， normal force， and friction coefficient exhibit a gradual decreasing trend. At a rolling speed of 100 m/s， the tangential force decreases by approximately 75%， the normal force by about 40%， and the friction coefficient by roughly 72%.