Abstract: The residual stress and hardness changes of ground surface play the key role in measuring the surface integrity of workpiece, and also have significant effect on the fatigue strength and wear resistance. Concerning grinding process under small cutting depth conditions in practical engineering, based on the grinding strength test of 45 steel specimens, the microstructure, thickness, surface hardness and residual stress of the grinding affected layer were studied. This work highlights the discussions of the formation mechanism and microstructure of the grinding affected layer. The results show that the surface residual tensile stress exists on the workpiece surface after dry grinding at small cutting depth. The residual stress tends to decrease with the increase of cutting depth or workpiece speed. The grinding affected layer thickness tends to increase with the increase of depth of cut or decrease of workpiece speed under small cutting depth conditions. The results indicate that reasonable grinding parameters and grinding wheel parameters can enhance the grinding capacity in dry grinding at small cutting depth.