Biological in-process dressing (BID) is an environmentally friendly dressing technique for metal based grinding wheel. In this study, different concentration Fe
3+solution containing acidithiobacillus ferrooxidans(A.f) was used as grinding fluid, comparing with water. The effects of different Fe
3+ concentrations on the grinding force, the surface roughness of the workpiece and the exposed height of the abrasive particles on the surface of the grinding wheel were compared and analyzed when the iron-based diamond wheel ground the single crystal silicon carbide with BID. The result shows that compared with the water group, BID can significantly reduce the normal force and tangential force in the grinding process. With the increase of Fe
3+ concentration in the biological dressing solution, the grinding force shows a downward trend, but the grinding force ratio first decreases and then slowly increases to 3.42. Biological dressing can also effectively reduce the roughness. The lowest surface roughness is 259.67 nm when the Fe
3+ concentration in the dressing solution is 3.0 g/L. The main reason for the above results is that the exposed height of the abrasive particles in the grinding wheel can be effectively increased through biological dressing.