The objective of this study is to verify the accuracy of performing surgery by developing and experimenting orthognathic surgical splints using 3D convergence technology. We performed the computation of the movement of the maxilla on the virtual simulation data for the surgery then designed the surgical splints using 3D CAD. We produced the designed splints and the test object and experimented on them using a 3D printer (accuracy ± 0.025 mm). The subjects were scanned using an optical scanner (accuracy ± 0.01 mm). We then compared and evaluated the simulated data and their accuracy. The evaluation results showed that the mean error range was within +0.313/-0.456 mm (average standard deviation 0.106), which was within the range of ±0.5 mm. These splints did not need for a reference point for external measurement to be set, neither did it need improving of the accuracy nor shortening the operation time. In addition, its advantage is that the amount of bone removal can be known accurately when the maxilla is repositioned.