Patho-occlusion, which is characterized by the abnormalities of denture, jaw and craniofacial region, is an oral disease with high incidence in all countries. Orthodontics has been widely employed for the treatment of patho-occlusion, during which the nickel-titanium (NiTi) arch wires with shape memory and superelastic properties play a vital role. With the great development of manufacture technology and clinical applications, surface coatings such as titanium nitride (TiN) have been introduced onto the NiTi arch wires for lower frictional coefficient, better wear resistance and greater biocompatibility. In particular, physical vapor deposition (PVD) is the most common method for TiN coating, but the transformation temperature of target NiTi wires will be greatly affected during the conventional PVD process. Here in this study, the direct current bias of conventional PVD process was changed to pulsed negative bias for fabricating TiN coating, which could retain the shape memory and superelastic properties of target NiTi wires by avoiding temperature rise. Different TiN coated NiTi arch wires were prepared by adjusting the frequency and duty cycle of negative bias, and the morphology and transformation temperature of various samples were systematically investigated. The results reveal that the PVD process with lower frequency and duty cycle is more suitable for the preparation of TiN coated NiTi arch wires and better clinical applications can be anticipated.