Provided is a method for plating a biocompatible coating with nano structure on the surface of a nickel-titanium shape memory alloy, particularly a method suitable for plating a coating on the surface of medical devices made of nickel-titanium alloy. The method includes the following steps: heat treating, surface pretreating, ion sputter cleaning, depositing a pseudodiffusion layer, plating a sub-layer film, plating a pure TiN layer, and so on. The coating has the following advantages: 1) it could deform in response to the deformation of substrate without delaminating and cracking； 2) it has less resistance to the deformation of substrate； 3) it has less penetrable holes so as to reduce the dissolution of nickel into bio-body through these holes； 4) the coating has better biocompatibility compared to the substrate material.
