Objective ·To preliminarily evaluate the execution accuracy of the self-developed cranial-maxilofacial robot (CMF ROBOT) system for genioplasty osteotomy of skull models. Methods ·Nine patients with chin deformity who were admitted to Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from August 2019 to October 2020 were included in the study. Before the operation, the spiral CT images of the whole head of the patients were collected, the skull models were made by 3D printing, and the virtual surgical planning was carried out. During the operation, the experimental group used CMF ROBOT system to perform automatic osteotomy on 9 skull models; the control group was manually osteotomized by senior surgeons assisted by 3D printing surgical guide plate. After the operation, spiral CT scanning was performed to measure the distance error and the direction error of the osteotomy plane of the two groups in three dimensions, and the differences of the two errors between the two groups were statistically analyzed. Results ·The osteotomy of genioplasty was successfully completed in the two groups. The distance error of the overall osteotomy in the experimental group was (1.40±0.27) mm and the direction error was 7.03°±3.02°, while the distance error of the overall osteotomy in the control group was (1.23±0.27) mm, and the direction error was 6.08°±2.24°. There was no significant difference between the two errors mentioned above (P=0.256, P=0.462). Conclusion ·The CMF ROBOT system can complete the automatic osteotomy of genioplasty according to the preoperative planning, and the distance error and direction error of the osteotomy surface can reach the precision level of manual osteotomy assisted by 3D printing surgical guide plate.