Objective To summarize the clinical experience of treating adults with pectus excavatum by newly modified orthopedicsteel plate and Nuss procedure. Methods The clinical data of 190 adults with pectus excavatum treated by newly modified Nuss procedure in Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine from January 2011 to June 2016 were collected. There were 151 males and 39 females aged 21.80±3.96 years ranging from 18 to 45 years. The therapeutic efficacy, Haller index and the lung function index were also analyzed. Results All patients recovered well after the operation. Two orthopedic steel plates were implanted in 12 patients. Pneumothorax was found in 7 patients postoperatively and 2 of them was treated by puncture extraction. There were 5 patients with poor healing of incision and all of them were healed after the debridement. Other complications such as steel plate shift was found in 2 patients. Both of them recovered after the reoperation. The duration of operation was 36–65 min. The intraoperative blood loss was 5–20 ml. Postoperative hospital stay was 4–7 days. Haller and lung function index improved after the operation (P<0.001). Conclusion It is effective and safe to treat the pectus excavatum by newly modified orthopedic steel plate and Nuss procedure in adult patients.