Objective To compare two image post-processing methods based on computed tomography angiography（CTA）—maximum intensity projection（MIP） combined with multiplanar reconstruction（MPR） versus subtracted volume rendering（VR） for morphological assessment of intracranial aneurysms，using three-dimensional digital subtraction angiography（3D-DSA） as the gold standard. Methods We retrospectively analyzed the CTA and DSA data of the head and neck of 92 patients involving 116 unruptured intracranial aneurysms in the First Affiliated Hospital of Chongqing Medical University. Double-blind measurement of the morphological parameters of intracranial aneurysms was performed on 3D-DSA VR images，CTA MIP-MPR images，and subtracted CTA VR images. Two measurements each were performed to calculate the average values，and relevant derived morphological indices were computed. The intraclass correlation coefficient（ICC） was used to assess the consistency of measurements between observers. The measurement results with different post-processing methods were compared using repeated-measures analysis of variance and the Friedman rank sum test. The Bonferroni correction was used for subsequent pairwise comparisons. The distribution of microaneurysms，small aneurysms，and wide-necked aneurysms between groups was compared using the chi-square test. Results The maximum diameter， width，and height of intracranial aneurysm measured with MIP-MPR，subtracted VR and DSA showed no significant differences（χ^２=4.484，5.808，and 4.468 respectively，all P>0.05）. The neck width and the mean diameter of the parent artery differed significantly among the three groups overall（χ^２=48.341，87.948，both P<0.001），Subsequent pairwise comparisons between any two groups revealed differences，with further differences also observed in terms of whether aneurysms were located at the siphon of the internal carotid artery or not. In addition，the derived morphological indicators measured with MIP-MPR were all greater，which were significantly different compared with DSA（P<0.017），and also significantly different compared with subtracted VR except for the height-to-width ratio（P<0.017）. In the morphological assessment of aneurysms based on subtracted VR，only the average diameter of the parent artery and the size ratio showed significant differences compared with DSA（P<0.017），and the difference in the average diameter of the parent artery was not significant in subgroup analysis；there were no significant differences in the other parameters between subtracted VR and DSA. Conclusion Subtracted VR is more accurate in measuring the morphological parameters of intracranial aneurysms than MIP-MPR，and is more suitable for morphological assessment of internal carotid artery siphon aneurysms.