The results of surgical simulation need to be transferred to the operation table with precision and confidence. We want to introduce a three-dimensional (3D)-printed maxillary cutting guide to perform the simulation-based maxillary osteotomy, interference removal, and the device guide for maxillary orthognathic surgery. The orthognathic simulation is performed with a horizontal osteotomy line and the maxillary segmental movement on a computed tomography (CT)-based 3D model. The maxillary cutting guide is designed as a band-shaped template encompassing the osteotomy line, bone interference area, and guiding holes. The design is exported to a 3D printer and the cutting guide is printed with biocompatible resin materials. The cutting guide was applied to 45 orthognathic surgeries. It could assist the easy and accurate osteotomy as planned and eliminate the repeated empirical checks of the premature interference site while preventing excessive bone reduction. This device guides the surgeon to place the osteotomy line, predict and remove the bony interferences, and place holes for additional surgical devices for maxillary orthognathic surgery.