Objective To compare the application of multi-slice spiral CT threedimensional reconstruction and X-ray in the diagnosis and treatment of pelvic fracture. Methods Seventy patients with pelvic fracture admitted to our hospital between May 2013 and May 2015 were examined by multi-slice spiral CT three-dimensional reconstruction and X-ray. According to the results of pathological examination, the two kinds of imaging examinations were compared in diagnosis of pelvic fracture. Results There were 113 fractures in 70 patients. The diagnostic rate of multi-slice spiral CT three-dimensional reconstruction for fractures of various parts was 100%. There were 5 cases with acetabular posterior lip, posterior column and sacroiliac fractures, 4 cases with acetabular midfeather fractures and 3 cases with acetabular roof, sacrococcyx and sacrum and iliac pterygoid bone fractures never diagnosed by X-ray. The diagnostic accuracy was 79.65%. There were no significant differences between multi-slice spiral CT three-dimensional reconstruction and X-ray in single and combined diagnostic rate of acetabular anterior lip, anterior column, acetabular roof, upper and lower branch of pubis, upper and lower branch of ischium, sacrococcyx, iliac pterygoid bone and pubis (P>0.05). The diagnostic rates of multislice spiral CT three-dimensional reconstruction for acetabular posterior lip and posterior column, acetabular midfeather and total fracture diagnostic rate were higher than those of X-ray (P<0.05). Conclusion Multislice spiral CT three-dimensional reconstruction can be used to diagnose various types of pelvic fractures, and the diagnostic rate is very high. It also can comprehensively and precisely reflect the stereo configuration of the fractured parts and pelvic three-dimensional shape.