Diamond-like carbon (DLC) films are widely applied in material protection due to high hardness, excellent wear resistance, and corrosion resistance. To solve the problem that 316L stainless steel is prone to wear and corrosion in the environment of marine friction and corrosion, Ta/TaN/TaCN/Ta-DLC films were deposited on 316L stainless steel by mid-frequency magnetron sputtering technology. The surface morphology, cross-sectional morphology, and corrosion morphology of the prepared films were observed by scanning electron microscopy (SEM). Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffractometer (XRD) were used to analyze the electronic structure of carbon element, chemical bond information, and phase composition in DLC films, respectively. The tribological and mechanical properties were tested by scratch method, nanoindentation test, and friction and wear test. The corrosion resistance of the films was tested by the electrochemical method. The effect of Ta element content in DLC film on the structure, composition, mechanical properties, tribological properties and corrosion resistance of the film was studied.