Abstract: Changes of surface material characteristics during the cutting process can easily cause surface fatigue damage. By cutting test of titanium alloy TC4, the influence law of feed rate on surface grain plastic deformation was studied, the TC4 cutting process was simulated using finite element simulation to obtain the cutting surface temperature and stress. Combined with experiment and simulationand, the connection between TC4 cutting surface grain change, cutting surface temperature and stress were explored. The results show that the plastic deformation degree of TC4 machined surface increases with the increase of feed rate, and the surface temperature and stress also increase with the increase of feed rate. Under the combination of surface temperature and stress, the surface grains appear elongated and torsional deformation, and the closer to the surface, the more obvious.