Objective To explore the value of multi-slice spiral CT (MSCT) postprocessing technique in the diagnosis of the causes of mechanical intestinal obstruction. Methods 95 patients with suspected intestinal obstruction by abdominal plain film in our hospital from September 2013 and March 2015were selected object. All patients underwent MSCT examination. The results were compared with the results of surgery or discharge. The diagnostic value of MSCT postprocessing technique in displaying the area of mechanical intestinal obstruction and its causes. Results In the 75 cases of patients undergoing surgical treatment, compared the sites displayed by MSCT with pathological results, the diagnostic coincidence rate was 90.67%. Location of obstruction occurred were the ileum, jejunum and ascending colon following. The coincidence rates of MSCT results were 83.33%, 93.10% and 100% respectively. The uncommon sites were the descending colon and rectum, and the coincidence rate of the results of MSCT was 80%. Compared the results of MSCT with clinically diagnosed results, it showed that the total coincidence rate was 84%. The coincidence rate in diagnosis of intestinal obstruction caused by tumors was relatively higher (94.44%). Conclusions MSCT postprocessing technique can exactly diagnose mechanical intestinal obstruction and the judgement of the location and causes of obstruction is accurate. It can be used as the preferred diagnosis of mechanical intestinal obstruction.