A method for treating a surface of a metal implant includes a polishing step, a grafting step and a surface modifying step. The polishing step includes polishing a surface of a metal implant to remove an uneven, natural oxide layer on the surface of the metal implant and to generate an even oxide layer on the surface of the metal implant. The grafting step includes grafting an anti-adhesion macromolecule on an outer face of the even oxide layer. A covalent bond between the anti-adhesion macromolecule and oxygen atoms on the outer face of the even oxide layer is formed. Thus, a macromolecular anti-adhesion layer on the outer face of the even oxide layer can be created. The surface modifying step includes changing a property of the surface of the metal implant with the macromolecular anti-adhesion layer by high temperature and high pressure, providing the metal implant with high hydrophilicity.