The structure of the nasal cavity varies greatly among individuals and is surrounded by many important tissues and organs. CT scan can clearly and directly show the fine structure of the patient’s nasal anatomy at different levels before surgery, so that the surgeon can clearly understand the lesion and its scope before surgery and provide a safe and reliable basis for nasal endoscopic surgery. The CT scan after surgery can also observe the postoperative sinus drainage and the recovery of the mucous membrane in the sinus. This is not possible with X-rays. However, this examination receives more rays than X-rays and should not be used continuously in the near future. It must be performed under the guidance of professionals to prevent unnecessary physical injuries.