A method for manufacturing a customized orthodontic square wire is disclosed. The present invention comprises: a step of generating a setup model in which teeth of a patient are rearranged to a normal position； a step of determining the position of a bracket on the setup model； a step of generating a reference line connecting slots of the determined bracket； a step of generating data for a cutting and grinding operation having a rectangular cross section by using the generated reference line； and a step of manufacturing a square wire by cutting a material using the data for the cutting operation of the generated reference line.
