Objective To investigate the value of spiral CT multi-phase enhanced scan in the diagnosis of renal cancer. Methods The CT imaging data of 115 patients with renal cancer confirmed by pathology in our hospital between April 2013 and August 2015 were analyzed retrospectively. The CT findings were observed. With surgical and pathological results as control, the diagnostic value of spiral CT multi-phase enhanced scan in staging and typing of renal cancer was evaluated. Results CT diagnosis showed that there were 50 cases in stage I of renal cancer, 35 cases in stage II, 20 cases in stage III and 10 cases in stage IV. Compared with surgical and pathological results, the total coincidence rate was 80.0%. There were significant differences in CT values of plain scan phase, arterial phase, parenchymal phase and excretion phase between patients with different subtypes of renal cancer (P<0.05). The CT values of clear cell carcinoma in arterial phase, parenchymal phase and excretion phase were significantly higher than those of chromophobe cell carcinoma and papillary carcinoma (P<0.05). The CT value of papillary carcinoma in plain scan phase (42.9±8.6) HU was significantly higher than that of clear cell carcinoma and chromophobe cell carcinoma [(36.6±6.0) HU, (35.7±5.3) HU] (P<0.05). CT showed that there were 84 round lesions; In terms of enhancement pattern, clear cell carcinoma was with inhomogenous enhancement and chromophobe cell carcinoma with homogeneous enhancement. Conclusion Because of features such as density and enhancement, the accuracy rate of spiral CT multi-phase enhanced scan in diagnosis of clinical stage of renal cancer is high, which is helpful to the diagnosis of renal cancer.