The work aims to improve thickness and various mechanical properties of TiN hard coating. Ti/TiN multilayer composite coatings were prepared by virtue of plasma enhanced PVD technology on the surface of Ti alloy (TC4) substrate. Microstructure of Ti/TiN coating was analyzed by using the scanning electron microscope (SEM). The bonding strength was characterized by means of scratch test, micro hardness was determined by Vickers and friction-wear resistance was evaluated by using ball-on-disk abrasion apparatus. The Ti/TiN multilayer composite coating prepared was 100 μm thick, free from such failures spalling. Its bonding strength was nearly three times than that of the monolayer TiN coating. Because of complex modulation of Ti and TiN multilayers, the micro hardness was up to 2700HV0.025. Meanwhile, the coating showed excellent self-lubricant and antiwear effects in addition to original favorable wear resistance. The friction coefficient of composite coating was about 0.25 after nearly 20 000 m of wear test without complete failure. The thickness of the hard coating can be improved by the multilayer composite structure and various mechanical properties of Ti/TiN multilayer composite coating are also enhanced remarkably.