Since hard tissues such as bone have a hierarchical structure with properties on many length scales from nano-level to macro-level, nanostructured titanium surfaces play an important role in hard tissue repair because they can mimic natural bone. Nanostructured surfaces can mimic the nanoscale properties of natural bone that promote bone cell adhesion, proliferation, and differentiation, as well as increase the surface area available for cell attachment, thus the contact area between the implant and the surrounding bone, improving the stability of the implant and its integration with the host tissue. Nanostructured titanium surfaces can also facilitate deposition of mineralized matrix and promote bone regeneration. In addition, the use of nanostructured surfaces can reduce the risk of implant failure and the requirement for additional surgical procedures. They can improve the long-term clinical outcomes of bone implants and reduce the likelihood of complications such as infection, inflammation, and rejection. Nanostructured titanium surfaces have significant potential to increase the efficiency of hard tissue repair and improve the quality of life of patients with bone injuries or disorders.