Objective To evaluate the application value of high-resolution computed tomography (HRCT) combined with thin-slice multi-planar reconstruction (MPR) in the imaging feature recognition of early-stage lung adenocarcinoma. Methods Clinical data from 96 patients with early-stage lung adenocarcinoma confirmed by surgery and pathology in our hospital between January 2023 and December 2024 were reviewed retrospectively. All patients underwent preoperative HRCT and thin-slice MPR. Nodule density, margin characteristics, internal findings, and relationships with adjacent structures were assessed. Using postoperative pathology as the reference standard, the diagnostic performance of HRCT alone was compared with that of HRCT combined with MPR, and sensitivity, specificity, and accuracy were analyzed. Results Among the 96 nodules, 42 were pure ground-glass nodules (pGGN) (43.8%), 39 were part-solid nodules (PSN) (40.6%), and 15 were solid nodules (SN) (15.6%). Spiculation, lobulation, and vascular convergence were observed more often in invasive adenocarcinoma (IAC). Compared with HRCT alone, the addition of MPR made lesion margins and internal details easier to recognize and allowed clearer assessment of the relationships between nodules and adjacent vessels, bronchi, and pleura. The correct recognition rate increased from 81.3% with HRCT alone to 91.7% with HRCT plus MPR, and the difference was statistically significant (P＜0.05). Conclusion HRCT combined with thin-slice MPR showed better overall performance than HRCT alone in the identification of imaging features of early-stage lung adenocarcinoma. It was more helpful for evaluating nodule morphology and adjacent structural relationships, and may improve preoperative imaging assessment.