Objective To summarize the CT findings and features of ankle joints with different fracture classification. Methods The clinical data of 22 patients with ankle fractures admitted to our hospital from July 2016 to July 2018 were analyzed retrospectively. All patients were diagnosed and classified by X-ray before surgery and given CT examination. The horizontal CT cross-sectional image at 1cm of ankle mortise near-end was selected, and the number of subtypes of Danis-Weber fracture classification and the number of various CT images were counted, and the correlation between the two method was analyzed. Results The a, b and c referred to fibular fracture, posterior malleolar fracture and interosseous ligament (IOL) fracture, and the CT images of 22 cases of ankle fractures could be summarized into the following 8 categories: 0 degrees in 3 cases (complete structures of fibula, posterior malleolus and IOL), Ia type in 1 case (fibular fracture, complete posterior malleolus, complete IOL), Ib type in 1 case (complete fibula, posterior malleolar fracture, complete IOL), Ic type in 3 cases (complete fibula, complete posterior malleolus, IOL fracture), IIab type in 7 cases (fibular fracture, posterior malleolar fracture and complete IOL), IIac type in 3 cases (fibular fracture, complete posterior malleolus, IOL fracture), IIbc type in 2 cases (complete fibula, posterior malleolar fracture, IOL fracture) and III type in 2 cases (a, b, and c fractures). CT images showed that the incidence rated of IOL fracture was increased with the severity of Danis-Weber classification, and the rank correlation test showed that there was a significant correlation between the two method(Spearman R=0.797, P<0.001). Conclusion CT cross-sectional image at 1cm of ankle mortise near-end can accurately determine the injury of tibiofibula combined with IOL before operation, and it has correlation with the Danis-Weber fracture classification, and it helps to find the missed diagnosis of X-ray.