The ultrasound of the thyroid gland is rich in blood flow and can be interpreted in two ways, which are helpful in determining the condition of thyroid nodular lesions and comparing before and after treatment, as follows: 1) for thyroid nodules, whether the blood flow is rich or not has no practical significance in determining the benignity or malignancy of the nodules; 2) for non-nodular lesions, such as hyperthyroidism, hypothyroidism, or Hashimoto’s thyroiditis, the ultrasound of the thyroid gland reveals When blood flow is abundant, the blood flow velocity of the superior arteries on both sides of the thyroid gland should be further examined. The presence of elevated blood flow velocity and combined with clinical symptoms can determine hyperthyroidism, hypothyroidism or Hashimoto’s thyroiditis and can give diagnostic hints. Of course, patients need to further combine with biochemical tests.