The CT manifestations of thyroid cancer are: 1. shape: in CT, the tumor of thyroid cancer resembles a starfish, or a pentagram, irregular in shape, oblong and similar to a jagged shape; 2. density: relatively lower compared to the density of the surrounding glands; 3. calcification: there will be a richer blood supply and many dense white calcified spots are seen in the tumor, all of which can be called the characteristic manifestations of thyroid cancer in CT; with the above 2- 3 conditions, the diagnosis of thyroid cancer can be basically confirmed. If 2-3 of the above conditions are present, the diagnosis of malignant tumor of thyroid gland can be basically confirmed. However, ultrasound is the first choice for the diagnosis of benign and malignant thyroid nodules, and its sensitivity and accuracy are much higher than CT.