Objective To evaluate the diagnostic value of CT scan and enhanced scan for mediastinal teratoma. Methods 53 cases of mediastinal teratoma were treated in our hospital from January 2014 to December 2016, collect the clinical data and imaging data of 53 cases, analyze the CT scan and CT enhanced scan of 53 patients with mediastinal teratoma, Pathological examination results were used as standard to compare the detection rate and diagnostic accuracy of CT scan and CT enhanced scan in mediastinal teratoma. Results The 53 patients with mediastinal teratoma, 22 were cystic teratoma (41.50%), there were 21 patients with benign parenchymal teratoma (39.62%) and 10 patients with malignant teratoma (18.86%). The total detectable rate and total accurate diagnosis rate of mediastinal teratoma by CT scan were 75.47% (40/53), 56.60% (30/53), and CT enhancement was 100% (53/53) and 96.22% (51/53), respectively, the total detection rate and total accurate diagnosis rate of mediastinal teratoma were significantly better than those of CT scan by CT enhanced scan, the difference was statistically significant (P<0.05). The cystic teratoma cases were benign lesions, and the CT scan showed cystic appearance, watery density, thin wall and smooth edge, CT enhanced scan showed that the tumor parenchyma, parenchyma and tumor were obviously strengthened, and there was no obvious enhancement in the tumor. The benign solid teratoma CT scan showed that the tumor capsule was intact, the superficial lobes were seen in the tumor, and the CT enhanced scan showed a slight inhomogeneous enhancement of the tumor. The parenchyma of the tumor was partly the density of soft tissue. CT scan of mediastinal malignant teratoma showed soft tissue density, mass image, irregular appearance, blurred boundary and surrounding tissue, there was no calcification in the tumor. CT enhanced scan revealed that the tumor broke through the envelope and invaded adjacent organs, the lesions showed inhomogeneous enhancement, with no obvious enhancement in the center. Conclusion CT enhanced scan can display the image features of mediastinum teratoma with high detection rate and high diagnostic accuracy, which can provide reliable imaging data for clinical treatment.