Background. Lung cancer is a common clinical thoracic malignant tumor, which had a serious impact on the safety of patients, currently ranking first in all malignant tumors in morbidity and mortality, with generally less than 5% survival rate in 5 years. Objective. To investigate the relationship and significance between carcinoembryonic antigen (CEA) and precursor gastrin-releasing peptide (ProGRP) changing levels in bronchoalveolar lavage fluid (BALF) and CT imaging features in patients with peripheral lung cancer. Methods. A total of 90 patients diagnosed with peripheral lung cancer as the lung cancer group and 60 patients with benign lung diseases as the control group in our hospital from May 2019 to October 2021 were selected to compare the differences of CEA and ProGRP in BALF by the classification of CT features. Results. The levels of CEA and ProGRP in the BALF of the lung cancer group were significantly higher than those of the control group; the proportion of patients with lobulation sign, burr sign, ground glass sign, pleural effusion, and lesion   diameter ≥ 3.0  cm in the lung cancer group was higher than that in the control group; the CEA level in BALF of lung cancer patients with spicule sign, pleural effusion, and lesion   diameter ≥ 3.0  cm was significantly higher than that without these symptoms, while ProGRP level in the BALF of lung cancer patients with lobulation sign, burr sign, ground glass sign, pleural effusion, and lesion   diameter ≥ 3 . 0 cm was significantly higher than that of lung cancer patients without these symptoms. Conclusion. The check of CEA and ProGRP in BALF in combination with CT features has a certain clinical value for the diagnosis of lung cancer. At the same time, the increased levels of CEA and ProGRP in BALF have a certain correlation with the changes of malignant signs of lung cancer in CT examination.