The surface structure was characterized by XRD, SEM, XPS and FTIR for the NiTi shape memory alloy (SMA) with a nearly-equiatomic ratio after composite bioactive treatment in H2O2 and subsequent NaOH solutions. The biomimetic deposition process of apatite coatings on the pretreated NiTi SMA was studied in the simulated body fluid (SBF). The experimental results indicate that a wormlike bioactive layer with many Ti-OH groups and a trait of Ni2O3 is formed on the NiTi substrate after the composite bioactive treatment, which was mainly composed of the poorly-crystallized Na2TiO3 and TiO2 and relatively poor in Ni. The bioactive layer can induce the apatite nucleation and growth in SBF and obtain an ideal apatite coating on NiTi substrate in a short term.