Objective To investigate the preoperative TNM staging, multi-slice spiral CT (MSCT) imaging findings and pathological features of patients with colon cancer. Methods The clinical data of 40 patients with colon cancer confirmed by surgery and pathology in our hospital between March 2009 and 2012 were retrospectively analyzed. MSCT was performed in all patients. The clinical data of all patients were analyzed retrospectively to evaluate the application value of MSCT imaging technology in the diagnosis of colon cancer. Results Thepreoperative TNM staging of patients with colon cancer was correctly diagnosed by MSCT in 35 cases(87.50%). For stage T1-2, there were 2 cases underestimated before operation. Pathological test showed that 1 case was stage T3 and 1 case was stage T4. There were 0 cases in stage T3 underestimated as stage T1-2 and 1 case overestimated as stage T4. In stage T4, there was 1 caseunderestimated as stage T1-2 and 1 caseunderestimated as stage T3. The diagnostic test consistency test showed Kappa=0.680(P<0.001). CT imaging findings of colon cancer showed intestinal wall thickened irregularly, masses inside and outside the lumen and relatively narrower intestinal cavity. Enhanced CT scanning showed masses with different degrees of enhancement, and the enhanced features was related to the degree of differentiation, while serosa and its adjacent organs were invaded. The serosal surface was coarse and surrounding fat layer was fuzzy, or with serosal stripped shadow, indicating that the surrounding organs were invaded, with regional lymph node metastasis, which was related to the location of tumor and reflux of the corresponding lymph nodes. Distal liver metastasis was common in organ metastasis. The postoperative pathological examination showed that Adenocarcinoma,signet ring cell carcinoma, tubular adenocarcinoma, mucinous adenocarcinoma, papillary adenocarcinoma, low molecular type adenocarcinoma cases were 18, 3, 5, 8, 3, 3. Conclusion MSCT is of good value in the evaluation of preoperative TNM staging of patients with colon cancer.