The machined workpiece has high mechanical storage energy because of the defect structures formed in nanocutting and their evolution from high energy state to the low energy state by adjusting atom positions automatically is called surface-energy aging. The effect of surface-energy aging on the surface properties of monocrystalline silicon workpiece is analyzed by Monte Carlo simulations of machined surface. It is shown that the surface-energy aging effect can increase the surface roughness and the degree of order of damaged layer, however reduce the residual stress and the average potential energy of workpiece. Amorphous silicon structure in metamorphic layer decreases and recrystallization phenomenon occurs in the surface-energy aging process. It is found that some β-Si phase structures and BCT5-si phase structures transform into the diamond cubic structure of Si in the surface-energy aging process. Surface-energy aging effect has a great influence on the surface properties of the machined surface of monocrystalline silicon workpiece, and can improve the mechanical properties of micro/nanostructures.