In this study, chemical methods were used to treat NiTi for the purpose of preparing bioactive NiTi implants. The surface of the bioactive NiTi alloy was investigated by XRD and ESEM. The biocompatibility and bioactivity of the bioactive NiTi samples were evaluated by in vivo implantation experiments. The results show that a Ca-P layer composed mainly of hydroxyapatite (HA) with a trace amount of other apatites and a Ca/P ratio of 1.59 covers the surface of the bioactive NiTi alloy. In vivo tests show that osteoblasts actively proliferated on the bioactive NiTi implants after 6 weeks implantation. A large amount of new bone directly in contact with the host bone was observed after 13 weeks implantation. These revealed the excellent biocompatibility and bioactivity of the prepared bioactive NiTi alloy.