Objective To explore the application of multi-slice spiral computed tomography (MSCT) three-dimensional reconstruction in the diagnosis of ankle fractures. Methods A total of 168 cases of patients suspected as ankle fractures admitted to the hospital from February 2017 to February 2018 were analyzed retrospectively, and they were given X-ray and MSCT examination and processed by post-three-dimensional reconstruction, including multi-planar reconstruction (MPR), maximum intensity projection (MIP) and volume rendering (VR). The results of clinical operation were used as the gold standard to compare the sensitivity, specificity and accuracy of the two methods for ankle fractures. The detection of the classification of ankle fractures (supination-adduction, supinationexternal rotation, pronation-abduction, pronation-external rotation, vertical compression type) was observed between X-ray and MSCT three-dimensional reconstruction. Results The sensitivity and accuracy of MSCT scan for ankle fractures were significantly higher than those of X-ray examination [(1.000 vs 0.933); (1.000 vs 0.935)], and the specificity of the two was the same. There were 11 cases of missed diagnosis of ankle fractures by X-ray (3 cases of supination-adduction, 2 cases of supination-external rotation, 2 cases of pronation-abduction, 2 cases of supination-external rotation, 2 cases of vertical compression), and the detection rate of ankle fractures by MSCT examination was 100%, but 1 case was misdiagnosed (taking 1 case of pronation-abduction as supination-external rotation). Conclusion Spiral CT is more reliable in the diagnosis of ankle fractures than X-ray, and the three-dimensional reconstruction has better detection of classification of ankle fractures, and it is conducive to the development of treatment regimens for late fracture surgery.