Objective To investigate the risk factors for postoperative complications Clavien-Dindo classification≥grade Ⅱ after lung cancer surgery. Methods The patients who underwent lung cancer surgery in a multicenter observational study from November 2017 to January 2020 were included. The Clavien-Dindo classification of postoperative complications was analyzed. Logistic regression was used to identify the risk factors for complications≥ gradeⅡ. Results A total of 388 patients were enrolled, including 203 males and 185 females with a mean age of 56.14±10.36 years. The incidence of postoperative complications was 25.52% (99/388) after lung cancer surgery and the incidence of complications≥gradeⅡ was 20.10% (78/388). The five most common postoperative complications were pneumonia (6.96%), prolonged pulmonary air leak (>7 days, 5.67%), incision dehiscence (4.64%), arrhythmia (3.87%), and postoperative pleural effusion (3.35%). Multivariate analysis showed that open surgery [reference: uniportal thoracoscopic surgery, OR=2.18, 95%CI (1.01, 4.70), P=0.047], extended resection [reference: sublobar resection, OR=2.86, 95%CI (1.11, 7.19), P=0.030; reference: lobectomy, OR=2.20, 95%CI (1.10, 4.40), P=0.026] and operative time≥3 h [OR=2.07, 95%CI (1.12, 3.85), P=0.021] were independent risk factors for postoperative complications≥gradeⅡ after lung cancer surgery. Conclusion Surgical approach, extent of resection and operative time are independent influencing factors for postoperative complications≥gradeⅡ after lung cancer surgery.