Objective To compare the value of multi-slice spiral CT three-dimensional reconstruction and X-ray in the diagnosis of acute ankle injury. Methods A total of 86 patients with acute ankle injury who were admitted to the hospital from June 2016 to June 2018 were selected. All patients underwent multi-slice spiral CT three-dimensional reconstruction and X-ray examination within 24 hours after injury. The diagnostic accuracy was compared between the two methods. Results Of the 86 patients with acute ankle injury, 12 cases were deltoid ligament injury, 18 cases were inferior tibiofibular syndesmotic disruption, 12 cases were interosseous membrane injury, 19cases were anterior ligament injury of lateral malleolus fibulae, and 25 cases were anterior inferior tibiofibular ligament injury. The diagnostic accuracy of multi-slicespiral CT threedimensional reconstruction [93.02% (80/86)] was significantly higher than that of X-ray examination [75.58% (65/86)] (χ2 =9.885, P<0.05). Conclusion Multi-slice spiral CT three-dimensional reconstruction can clearly show the type of acute ankle injury from multiple directions and multiple angles, avoiding image overlap. The application value is significantly higher than X-ray and it can provide important basis for the development of clinical treatment plan.