The epoxy resin (EP)/polytetrafluoroethylene (PTFE) coatings were made on the silane coupling agent modified TiNi alloy teeth corrective wires by dipping. The influence of silane coupling agent concentration on the adhesion force between the coatings and TiNi alloys was investigated, and the mechanism of the improvement of the adhesion force due to the induction of the silane coupling agent was revealed. The effect of epoxy resin (EP)/polytetrafluoroethylene (PTFE) coatings on the biocompatibility and Ni ions release from the TiNi alloys was investigated. In addition, the difference between the coated and uncoated TiNi alloy teeth corrective wires was compared. The results show that the concentation of silance coupling agent has a great influencer on the adhension force between the coating and TiNi alloy. With the increase of the concentation, the adhension force increases first, then decreases. EP/PTFE coating can inhibit Ni ions precipitation from TiNi alloy, and has a good biocompatibility.