ObjectiveTo explore the efficacy of single-port thoracoscopic anatomical lung segmentectomy in treating Stage IA non-small-cell lung cancer (NSCLC) and to analyze its impact on the body's stress response and lung function. MethodsA retrospective analysis was conducted on the clinical data of patients with stageⅠA NSCLC admitted to the Second Affiliated Hospital, Air Force Military Medical University, from January 2021 to June 2022. Patients were divided into two groups based on their treatment plans: those who underwent single-port thoracoscopic lobectomy were in the lobe group, and those who underwent single-port thoracoscopic anatomical lung segmentectomy were in the segment group. The surgical-related indicators, complication rates, survival rates of the two groups were compared, as well as the body's stress response indicators before and after surgery [C-reactive protein (CRP), interleukin-6 (IL-6), cortisol (Cor), creatine kinase (CK)], prognostic lung function indicators [forced vital capacity (FVC), maximal voluntary ventilation (MVV), forced expiratory volume in one second (FEV1), FEV1/FVC ratio], and auxiliary tumor markers [carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125), CA724, cyto-keratin 21-1 fragment (CYFRA21-1)]. ResultsEach group included 53 patients, with 29 males and 24 females in the segment group, with an average age of (70.38±3.67) years; and 26 males and 27 females in the lobe group, averaging an age of (71.09±3.80) years. The intraoperative blood loss in the segment group was less than that in the lobe group [(118.41±14.58) mL vs. (130.36±10.61) mL, P＜0.001], and the hospital stay was shorter in the segment group [(7.13±1.14) d vs. (8.52±1.33) d, P＜0.001]. One day and three days post-surgery, the serum levels of CRP, IL-6, Cor, and CK in the segment group were lower those in the lobe group, while the levels of FVC, FEV1, FEV1/FVC ratio, and MVV were higher (P＜0.05). One month and three months post-surgery, the serum levels of CEA, CA125, CA724, and CYFRA21-1 in the segment group showed no statistically significant difference compared to the lobe group (P＞0.05); the incidence of postoperative complications and survival rates in the segment group were 3.77% and 80.39%, respectively, while they were 7.55% and 76.92% in the lobe group, respectively, with no statistical difference between the two groups (P＞0.05). ConclusionSingle-port thoracoscopic anatomical lung segmentectomy for stage ⅠA NSCLC has significant advantages in reducing intraoperative damage, stabilizing the body's stress response, and has less impact on lung function, which is beneficial for postoperative recovery.