Abstract: In order to solve the problem that subsurface damage of diamond material is difficult to detect, this paper is based on molecular dynamics theory and method. A three-dimensional simulation model of double grits grinding is established for analysis, and the influence of different grinding rake angle on grinding force and material damage is studied. The simulation analysis results show that grinding force can be reduced by increasing the grinding rake angle, and the influence of normal grinding force is more obvious. The average coefficient of friction of negative grinding rake angle is smaller, which makes it easier to achieve the removal of diamond atoms; The subsurface damage of the diamond material under negative grinding rake angle grinding is larger. The undulating change of subsurface damage can be reduced and the subsurface damage can be improved by increasing the grinding rake angle.