Despite the widespread use of titanium alloys in various fields, surface defects that arise during the processing of Ti-6Al-4V can significantly reduce their service life. Therefore, developing a new approach to enhance the performance of TC4 alloys, particularly in challenging environments such as high-wear and wet conditions is crucial. This study proposes a novel method to create a hardened surface enriched with TiN using nitrogen gas-assisted electrical discharge machining (NA-EDM). The aim was to assess the impact of surface modification via NA-EDM on anti-wear and anti-corrosion performance across different peak currents and to explore the mechanism behind the surface's hydrophobic properties. The findings show that the NA-EDM process produces fewer surface defects compared to traditional EDM. Moreover, NA-EDM treatment significantly improves surface hydrophobicity, as evidenced by a 21.25 % increase in the contact angle (CA). Furthermore, the NA-EDM-treated surface exhibits enhanced resistance to wear and corrosion, with a notable 14.9 % reduction in wear rate and average friction coefficient.