A method of generating a digital supplementary device for dental implantation by: preparing a mouth model based on the internal shape of the oral cavity of the patient; performing a 3D scan to obtain digital model of the mouth model, the digital model of the patient's oral cavity and the digital model of the tooth model; defining the digital models as the “positioning object,” “the reference object” and the “attached positioning object”; obtaining characteristic points after joining the positioning object and the attached positioning object and positioning the positioning object and the reference object based on the characteristic points; and then outputting the attached positioning object with the positioning data obtained after positioning of the attached positioning object. The output thus obtained is the desired digital supplementary device for dental implant planning.