Objective To explore the accuracy of magnetic resonance imaging (MRI) and multi-slice spiral CT (MSCT) in the diagnosis of occult fractures of ankle joint. Methods The clinical data of 69 patients with occult fractures of ankle joint who were treated in orthopedics department of our hospital from May 2016 to May 2018 were analyzed retrospectively. X-ray examination of all patients was negative or suspicious ankle fractures, and MRI and MSCT were performed in patients within 7 d after trauma. Surgical pathological examination was used as the "gold standard" to analyze the diagnostic accuracy of occult fractures of ankle joint by MRI and MSCT, and the diagnostic differences between the two methods were compared. Results MRI findings of occult fractures of ankle joint, T1WI sequence showed schistose and uneven low or slightly low signal, and T2WI sequence showed high or slightly high signal, and STIR sequence showed obvious high signal. MSCT findings showed interruption of bone continuity or fracture line shadow, and displaced fracture and local fracture defect were consistent. The diagnostic sensitivity and accuracy of MRI were higher than those of MSCT (P<0.05), and the specificity was slightly higher than that of MSCT (P>0.05). Conclusion MRI and MSCT have high diagnostic value for occult fractures of ankle joint, but MRI has higher sensitivity and accuracy, and it can be used as the first choice for examination to provide more accurate imaging data.