Thyroid cancer has various manifestations. If the nodule is small and only a hypoechoic nodule with fuzzy border can be seen, then the patient will be advised to review or have a direct puncture biopsy. Generally, when thyroid nodules are larger than 3-5mm, ultrasound can clearly show their borders and internal echogenicity, and only then can the nodules be described or malignant signs be captured, as follows: 1) hypoechoic nodules with irregular edges, because malignant nodules invade the adjacent thyroid gland, and there are early and late invasion, so there will be an echogenic change; 2) nodules with disproportionate aspect ratio, and disproportionate aspect ratio is a higher weight in diagnosing thyroid cancer. Microcalcification is a typical malignant ultrasound feature, with posterior echogenic attenuation and elasticity signs showing high hardness of the nodule; 4.