Due to the high grinding speed and the less contact length, there is the super high material strain rate in the contact layer during quick-point grinding process. Based on the principle of micro-damages mechanics, it is the impact process between the workpiece and the grits on the wheel in the process. The weakening effects of the super high strain rate caused by the mechanical impact micro-damages and the adiabatic shearing damage can lower the dynamic strength of the material in contact layer and the micro-plastic pile-up deformation on the ground surface in the process. Therefore, it is possible to improve the surface integrity of the workpiece since the materials removal mechanism is changed in quick-point grinding process. In this paper, the impact performances and the model of quick point grinding process were studied. Based on the above, the model of the ground surface roughness related to the plastic pile-up deformation was established. The effects of the strain rate on the ground surface roughness and the materials removal ratio were analyzed. In addition, the grinding experiment was performed to testify such investigations. It is indicated that quick-point grinding is an impact process assuredly during the removing material process.