In this research, based on the concept of surface engineering and composite multi-component structure design, the titanium-doped diamond-like carbon (DLC) films were prepared on the surface of titanium alloy threaded fasteners by microwave plasma enhanced magnetron sputtering technique. Titanium-doped DLC composite films with different structures and properties were prepared by regulating acetylene flow. The microscopic morphology of titanium-doped DLC films were analyzed by transmission electron microscope. The microstructure, residual stress, nano-hardness, adhesive strength and wear properties were studied by XRD, Raman spectrometer, profilometry technique, nanoindenter and friction test machine. The results show that TiC crystalline phase is formed in titanium-doped DLC films, and the residual stress of titanium-doped DLC film can be effectively reduced with appropriate acetylene gas flow. The sp³ hybrid bond content is decreased gradually with the increase in acetylene flow. The titanium-doped DLC film with acetylene gas flow of 0.025 L/min has higher hardness, elastic modulus, toughness and the largest H/E and H³/E² ratios, which can resist the scratch of the indenter. Therefore, the film maintains good adhesion in the scratch, and has the best wear resistance, which can effectively improve the service life of titanium alloy fasteners.