In this paper, based on the concept of surface engineering and composite multi-component structure design, the titanium doped DLC films with different acetylene gas flow rate were prepared on titanium alloy threaded fasteners by microwave ECR enhanced magnetron sputtering technology. The microscopic morphology of titanium-doped DLC films were analyzed by transmission electron microscopy. The structure, residual stress, hardness, adhesive force and wear properties were studied by XRD, profilometry technique, nanoindenter and friction test. The results showed that nanometer TiC crystalline grains was formed in titanium-doped DLC films, and the residual stress of titanium doped DLC film can be effectively reduced by suitable acetylene gas flow rate. The sp3 hybrid bond content decreases gradually with the acetylene flow rate increasing. The titanium doped DLC film with acetylene gas flow rate of 25 sccm had higher hardness elastic modulus and toughness, and can resist the scratch of the indenters, excellent toughness and crack deformation resistance, had the best adhesion strength and wear resistance due to the high H/E and H3/E2 ratios, which can effectively improve the service life of titanium alloy fasteners. The results have certain reference value and theoretical basis for the preparation and application of high-hard wear resistance composite film on titanium alloy threaded fasteners.