A method for producing a support structure of a 3D model for 3D printing is provided. A method for producing a support according to an embodiment of the present invention comprises the steps of: dividing a surface constituting a 3D model into multiple surface patches; classifying respective divided surface patches according to geometric characteristics; and producing supports corresponding to the classified characteristics with regard to respective surface patches. Accordingly, during metal laminate manufacturing, the output stability may be improved while reducing the support producing process time. In addition, the surfaces may be expressed by different colors according to the result of geometric characteristic classification, and the supports may also be expressed by different colors according to the type, thereby playing the role of guide lines such that the user can recognize the shape of the surfaces and the type of supports to be installed on the corresponding surfaces. Moreover, the size of a support tip is determined in view of the thickness of the area in which a support is to be produced, thereby preventing the problem of output quality degradation which would otherwise occur because the support cannot move upwards through an output part.