Doping is an important way to improve the thermal stability and tribological properties of diamond like carbon (DLC) films.The DC magnetron sputtering technology was used to deposit hydrogen containing DLC film on the surface of the 304 stainless steel substrate,and the radio frequency magnetron sputtering technology was used to complete the doping of Cr element in the film.Effect of the doping of Cr element on the mechanical properties and tribological properties of DLC films were studied.The film hardness was tested by nanoindentation test machine,and the bonding force of the film base was measured by the scratch experiment.Raman spectroscopy was used to analyze the changes in the sp2 and sp3 bond content and the existence of transfer film.UMT-TriboLab tribotest was employed to evaluate the tribological properties of Cr-doped DLC at room temperature and high temperature environment.The wear surface was observed by scanning electron microscope (SEM) to analyze the wear mechanism.The results show that the doping of Cr element greatly enhances the film-base bonding force,while the hardness of the film is slightly reduced.The tribo-tests at room temperature show that the friction coefficient of Cr-doped DLC film increases initially and then decreases with the increase of Cr content,and the Cr-doped DLC with Cr mass fraction of 3.53% possesses the lowest friction coefficient.However,the wear rate of the doped films of DLC is slightly higher than that of the pure DLC film at room temperature.The tribo-tests at high temperature exhibit that the doping of Cr element improves the high temperature tribological properties of the DLC film.The undoped DLC film fails when rubbed above 150 ℃,while the Cr doped DLC film maintains low friction coefficient and long anti-wear life at 250 ℃.The doping of Cr element improves the bonding strength,reduces the friction coefficient and enhances the high temperature tribological properties of the DLC film,which may be attributed to the transformation of the film structure due to the doping of Cr element and the produced oxide of Cr playing a protective role for high temperature resistance.