The characteristics of ultrasonography for thyroid cancer include the tumor being a solid hypoechoic mass with unclear boundaries, uneven internal echoes, abundant internal blood flow, and the presence of sandy calcifications and longitudinal growth, among others. Currently, ultrasonography is the preferred method for examining thyroid nodules. It can clearly identify the number, nature, and location of thyroid nodules, as well as whether there are any abnormally enlarged lymph nodes in the neck. Ultrasonography is highly accurate in differentiating the nature of thyroid nodules, with experienced ultrasonographers reaching an accuracy rate of over 80%. However, the highest accuracy in differentiating the nature of thyroid nodules is still achieved with fine-needle aspiration cytology.