Objective To investigate the value of multi-slice spiral CT multi-planar reconstruction (MPR) in the diagnosis of central and peripheral lung cancer. Methods The preoperative CT imaging data of 96 patients with lung cancer (including 52 cases of central type and 44 cases of peripheral type) which confirmed by transbronchial pathology or surgical pathology in our hospital for nearly one and a half years were collected. The display effects of conventional trans-axial thin-layer scan images and MPR reconstructed images on lung cancer were compared, and the diagnostic value of MPR was analyzed in central and peripheral lung cancer. Results The mean thickness (T) of bronchial and bronchial branches of central lung cancer were (8.01±1.24) mm and (14.71±3.58) mm measured by trans-axial thin-layer scan and MPR respectively, and the average length (L) of tube wall thickening were (14.16±2.79) mm and (22.54±4.57) mm respectively, and the T/L ratio were 0.56 and 0.62 respectively, and there were significant differences in the T and L of tube wall thickening of central lung cancer leaf and segmental bronchial branches measured by transaxial thin-layer scan images and MPR reconstruction images (P<0.05). Transaxial thin-layer scan showed there were 35 cases of short spurs in peripheral lung cancer, 28 cases of deep lobulated sign, 20 cases of vocule sign, 30 cases of bronchial vascular bundle sign, 30 cases of pleural indentation and 19 cases of air bronchogram. MPR showed there were 40 cases of short spurs in peripheral lung cancer, 35 cases of deep lobulated sign, 22 cases of vocule sign, 41 cases of bronchial vascular bundle sign, 38 cases of pleural indentation and 37 cases of air bronchogram. There were significant differences in the deep lobulated sign, bronchial vascular bundle sign, air bronchogram and pleural indentations of peripheral lung cancer by transaxial thin-layer scan and MPR (P<0.05). Conclusion MPR can show the lesions of central and peripheral lung cancer more clearly, which help to improve the accuracy of CT diagnosis of lung cancer, and guide the clinical formulation of a reasonable surgical program, and improve the treatment effect of lung cancer.