Objective To study the clinical value of 64 slice spiral CT in the diagnosis of occult lesions and soft tissue injury after knee trauma. Methods A total of 100 patients with knee trauma treated in the hospital from April 2015 to July 2017 were selected as study subjects. All patients were examined with X-ray and 64 slice spiral CT, and X-ray diagnosed 55 patients with suspected tibial plateau fractures. The diagnostic efficiencies were compared between the two methods for tibial plateau fractures. The detection rates of tibial plateau fractures were compared between X-ray and 64 slice spiral CT. The display and imaging findings of the two examination methods for collapse degree of fractures and horizontal dislocation were analyzed. Results Of 100 patients with knee trauma, 55 patients had suspected tibial plateau fractures, accounting for 55.00%. The sensitivity and accuracy of 64 slice spiral CT in the diagnosis of tibial plateau fractures (80.00%, 70.00%) were significantly higher than those of X-ray (60.00%, 60.00%) (P ＜0.05), while the specificity showed no significant difference between the two methods (78.18% vs 60.00%) (P＞0.05). The detection rates of 64 slice spiral CT in type I, II, III, IV, V and VI tibial plateau fractures were slightly higher than those of X-ray, and total detection rate (86.67%) was significantly higher than that of X-ray (60.00%) (P＜0.05). The detection rates of the collapse degree of fractures and horizontal dislocation by 64 slice spiral CT (42.22%, 48.89%) were higher than those of X-ray (17.78%, 13.33%) (P ＜0.05). 64 slice spiral CT was superior to X-ray in the display of occult lesions and soft tissue injury in tibial plateau fractures. Conclusion 64 slice spiral CT has more advantages over X-ray in the diagnosis of knee joint fractures. It can well display post-traumatic occult lesions and soft tissue injury through multi-plane and multi-angle imaging, and improve the diagnostic sensitivity and accuracy.