Based on the molecular dynamics simulation (MDS) method, this article built up a molecular dynamics (MD) model of titanium nanometric cutting, chose representative cutting conditions, obtained the instantaneous image of atomic position through simulation and analyzed the material removal phenomenon, surface formation process, change rules of system potential energy and workpiece temperature in cutting process. It is found that the formation of the chips and the machined surface in cutting process are caused by the release of lattice energy and the lasting expansion of dislocation. The elastic recovery and lattice reconstruction of the machined surface and can slow down the increasing trend of total potential energy and temperature, and make them accompanied by slight fluctuations.