Titanium and its alloys have become the primary materials for orthopedic implants due to their excellent biocompatibility, mechanical properties, and corrosion resistance. However, traditional manufacturing techniques struggle to achieve complex porous structures, and their insufficient surface bioactivity limits their clinical performance. Additive manufacturing (AM) technology enables the precise fabrication of titanium implants with personalized shape, biomimetic porous structures, and gradient mechanical properties. The controllable porosity, pore size, and pore shape not only achieve mechanical compatibility with human bone tissue, but also provide an optimal microenvironment for cell adhesion, proliferation, and vascularization. During the process of designing porous structures, the auxiliary roles of finite element analysis (FEA) and machine learning (ML) play a crucial role in performance prediction and process optimization. To further enhance the bioactivity of AM titanium alloys, surface modification techniques such as mechanical, physical, chemical, and electrochemical methods have been widely employed. These modified coatings significantly improve the osseointegration efficiency, antibacterial properties, and corrosion resistance of implants without compromising the mechanical integrity of the substrate. Currently, AM titanium alloy implants have been successfully applied in joint replacements, dental prosthetics, and other fields. Through the synergistic effect of personalized design and surface functionalization, they demonstrate superior clinical application potential compared to traditional implants. This article systematically reviews the porous structure design, surface modification techniques, and application progress of AM titanium alloy implants, aiming to provide valuable insights for clinical applications.