Disclosed is a method of manufacturing a digital overdenture. The method includes a first operation of aligning and setting a plurality of pieces of implantation information of fixtures according to alveolar bone information in a planning image, a second operation of designing and manufacturing a surgical guide and a holder abutment mounting guide, a third operation of preparing a temporary denture corrected to form a temporary holder insertion portion having an inner surface part into which a holder device is inserted to be shape-matched therewith, in which the surgical guide is installed in the target arch to implant the fixtures and the fixing bar is fixed to the holder abutments moved to and coupled with top ends of the fixtures by the holder abutment mounting guide, and a fourth operation of manufacturing a digital overdenture including an artificial tooth portion and an artificial gum portion.