Objective To investigate the value of multi-slice spiral CT features combined with tumor markers in the diagnosis of lung cancer. Methods 137 cases of suspected lung cancer patients were treated in our hospital from March 2016 to April 2017, there were 83 cases of final diagnosis of malignant lesions, and 54 cases of benign lesions, all patients were examined by MSCT scan and tumor standard CA125, CEA and NSE were detected. Results CA125, CEA and NSE in malignant lesions were significantly higher than those in benign lesions (P<0.05). The sensitivity of MSCT combined with tumor markers in the diagnosis of malignant lesions was 95.18%, which was significantly higher than that of MSCT, CA125, CEA and NSE (P<0.05). The specificity of MSCT combined with tumor markers in the diagnosis of malignant lesions was 90.74%, which was significantly higher than that of CA125, CEA and NSE (P<0.05). The CA125 of non small cell lung cancer was significantly higher than that of small cell lung cancer (P<0.05), while NSE was significantly lower than that of small cell lung cancer (P<0.05). In the MSCT characteristics of non-small cell lung cancer, the percentage of bronchial truncation, uneven density and /or necrosis were 82.81% and 75%,which were significantly higher than those of small cell lung cancer (P<0.05), the proportion of pleural effusion was 18.75%, which was significantly lower than that of small cell lung cancer (P<0.05). Conclusion The combination of MSCT features and tumor markers has a good application value in the diagnosis of lung cancer, and it has a certain role in the differential diagnosis of small cell lung cancer and non-small cell lung cancer.