Objective To study the imaging findings and diagnostic value of multi-slice spiral CT (MSCT) in primary tracheal tumors. Methods 19 cases of patients with primary tracheal tumors confirmed by pathology in our hospital were selected as the research objects. Routine plain scan and enhanced scan were performed by GE Light Speed QX/ i MSCT scanner and the data were analyzed by AW workstation to get MPVE, VR and VB images. The images were read by 2 imaging physicians in our hospital. The growth direction, shape, density and other pathological features of tracheal tumors were mainly observed to find out the relationship with pathological diagnostic results, so as to evaluate the value of CT imaging in the diagnosis of primary tracheal tumors. Results In this study, all of the 19 patients underwent enhanced scan. The results showed that the enhancement values of malignant tumor and low-grade malignant tumor were relatively lower, which were 15-38hu and 21-44hu, respectively. Benign tumor were significantly enhanced and the enhancement value of a patients with benign tumor were 30Hu. 19 patients were examined by CT and 4 cases of low-grade malignant tumors were intracavity wide basal node type, 3 cases were with salivary gland cancer and a case with tracheal mucous epidermoid carcinoma. There was 1 case of tube wall growth infiltrating type and 1 case with low-grade malignant adenoid cystic carcinoma; 1 case was benign tumor of intracavity narrow basal nodular type; There were a total of 3 cases of mass type in the inside and outside of the cavity and all belonged to malignant tumors, including 1 case of squamous cell carcinoma, 1 case of adenocarcinoma and 1 case of mucosa associated lymphoma; 10 cases of tracheal carinal tumor type belonged to malignant adenocarcinoma and squamous cell carcinoma. Conclusion CT can be used to identify the benign and malignant primary tracheal tumors by observing the growth direction, density and shape of the primary tracheal tumors. It can be used to identify malignant and low-grade malignant tumors.