Disordered-orientation TiO2 nanotube array films were prepared by constant-potential anodization of a novel near-β titanium alloy Ti-5Zr-3Sn-5Mo-25Nb (TLM). The TiO2 film can induce the deposition of the apatite to form HA in simulated body fluid (SBF), indicating that the film does not restrict early adhesion of the osteoblast and possesses good biocompatibility. By comparison, it is found that the adhesion ratio of osteoblast on TLM with disordered-orientation TiO2 nanotube array films after soaking in SBF for 3 d is obviously higher than that of Ti sheet with TiO2 nanotube arrays, and the cellular morphology is excellent. It is concluded that the anodization can further improve the biocompatibility and bioactivity of TLM titanium alloy.