BACKGROUND: Studies on the biomechanical properties in NUSS procedure have obtained some achievements, but the effect of scoliosis surgical correction of scoliosis on thoracic deformity remains unclear.OBJECTIVE: To explore the effect of simultaneous correction of pectus excavatum and scoliosis on thoracic deformity so as to provide reference for designing a rational orthopedic scheme.METHODS: The three-dimensional reconstruction model of the chest was established based on the CT data of the patients with pectus excavatum and scoliosis. The surgical correction of pectus excavatum and scoliosis was simulated by numerical simulation method.RESULTS AND CONCLUSION: (1) Results after correction showed that the bilateral spinous processes at T3-5 segments displaced to the left (X direction) about 1 mm, suggesting that the simultaneous correction is favorable for the correction of scoliosis. (2) Compared with the single NUSS procedure, the displacement at Y direction was increased by 13.358 mm in the simultaneous correction; meanwhile, there was significant difference in the shortest displacement between two methods.(3) In views of Von Mises stress distribution, the stress in the simultaneous correction was decreased by 24.6 MPa compared with the single Nuss procedure, indicating that the simultaneous correction can significantly reduce the Von Mises stress on the chest, which contributes to alleviate the postoperative pain. (4) Our results show that the simultaneous correction cannot only improve scoliosis, but also improve the symptoms of pectus excavatum.