Objective To introduce a novel classification method for pectus excavatum. Methods A retrospective review of 569 operative patients with pectus excavatum between January 2015 and September 2017 in our hospital was performed. The malformations were described and classified from three dimensions: symmetry (abbreviated as S), depth (abbreviated as D) and position (abbreviated as P). The final integral was calculated according to the deformity index, so that the severity of the deformity could be evaluated. All patients underwent Nuss or modified Nuss surgery. Results All pectus excavatum deformities were classified into 24 types. The most common type was S1D2P1, accounting for 27.2% of the total patients followed by S1D2P2, S1D1P2 and S2D2P2, accounting for 12.0%, 11.6% and 11.4% of all patients respectively. S1D3P3, S1D3P4 and S2D3P3 were not found in our patients. According to the integral, 321 patients were mild, 23 severe, and the rest were moderate. The appearance of all patients improved after the operation. Among them, 405 patients were implanted with a plate, 159 with two plates and 5 with three plates. The length of hospital stay was 5-12 d, with an average of 7.3±1.5 d. Conclusion This classification method is a more comprehensive classification, but its scientific and practical characteristics need to be further confirmed.