In order to analyze the effect of proceeding on the mechanical and tribological properties of DLC films.We prepared three DLC films samples on single silicon wafers by CVD method.The changed bias voltage is 300 V(DLC300)、350 V(DLC350)、450 V(DLC450) separately.The structure and topography of prepared films were studied by Raman spectroscopy and atomic force microscopy (AFM),respectively.The hardness (H) and elastic modulus (E) together with friction coefficient of DLC films were measured by Tribolab system.According to the Raman spectra,the apex of G appears in the range of 1 400~1 700 cm-1 and the apex of D appears in 1 200~1 450 cm-1 identify that the film is DLC.The topography of the three DLC film samples was measured by AFM.It shows that the increasing bias voltages will improve the surface quality by controlling the size of crystal grains.The H of the DLC films decrease with the increasing of bias voltages,and the H value of DLC300,DLC350,DLC450 is 19.63 GPa,19.16 GPa,18.13 GPa separately.