The invention relates to waterborne polyurethane resin for printing ink on the surface of toughened glass and a preparation method of the waterborne polyurethane resin. A polymer synthetic monomer with special performance is introduced into to the waterborne polyurethane resin, and polymer synthesis modification is carried out. When the synthesized waterborne polyurethane resin is used as a binderof waterborne tempered glass surface ink, the wetting, spreading and binding force of the waterborne ink on the surface of tempered glass during printing can be increased, the surface energy of the surface of the tempered glass is reduced, and the problem of surface binding adhesive force during printing of the waterborne polyurethane ink on the surface of the tempered glass is solved.