Objective  To explore the relative positioning of the superior orbital fissure and internal carotid artery through CT three-dimensional reconstruction, and to provide anatomical references for safe dissection during surgeries involving the orbital apex from a radiological perspective.   Methods  Totally 64 cases (128 sides) of head and neck CT angiography were analyzed and Mimics 21.0 software was employed for three-dimensional reconstruction. Measurements were taken on the three-dimensional models, including the distance from the inner boundary of the superior orbital fissure to the anterior convexity, proximaldural ring, and distaldural ring of the internal carotid artery. Distances were also measured from the lower boundary of the superior orbital fissure to the anterior convexity, proximaldural ring, and distaldural ring of the internal carotid artery. Additionally, measurements were taken from the upper boundary of the superior orbital fissure to the anterior convexity, proximaldural ring, and distaldural ring of the internal carotid artery. Patient demographic data such as gender, age, and sphenoid sinus aeration were recorded, and anatomical variations were analyzed in correlation with the measured result.   Results  Distances were measured as follows, d1 (6.32 ± 1.98)mm, d2 (7.13 ± 2.66)mm, and d3 (9.88 ± 2.29)mm from the inner boundary of the superior orbital fissure to the anterior convexity, proximaldural ring, and distaldural ring of the internal carotid artery, respectively. Distances were also measured as d4 (11.93 ± 2.17)mm, d5 (10.39 ± 2.36)mm, and d6 (16.18 ± 2.28)mm from the lower boundary of the superior orbital fissure to the anterior convexity, proximaldural ring, and distaldural ring of the internal carotid artery, respectively. Distances from the upper boundary of the superior orbital fissure to the anterior convexity, proximaldural ring, and distaldural ring of the internal carotid artery were measured as d7 (7.91 ± 2.55)mm, d8 (9.63 ± 2.99)mm, and d9 (10.09 ± 2.72)mm, respectively. The relative distance between the superior orbital fissure and the cavernous segment of the internal carotid artery was significantly greater in males than in females. In patients under 20 years of age, d7~d9 were significantly smaller than in patients over 20 years old, with statistically significant differences. There was a correlation between the type of sphenoid sinus aeration and the main measured parameters d1-d6, while the degree of sphenoid sinus aeration and the presence of the superior orbital fissure were not significantly correlated with the main measured parameters.  Conclusion  Three-dimensional reconstruction based on CT angiography provides a better assessment of the distance between the superior orbital fissure and internal carotid artery. This method  holds clinical reference value for orbital apex surgeries and ensures a safe dissection distance.