Papillary thyroid carcinoma is the most common histological type of malignant thyroid tumor. The central cervical lymph nodes，particularly Delphian lymph nodes，are the first areas affected by metastasis in papillary thyroid carcinoma. Early diagnosis of Delphian lymph node metastasis is crucial for determining the treatment approach and improving survival prognosis of patients. Ultrasound is the preferred method for diagnosing lymph node metastasis in papillary thyroid carcinoma. This review focuses on the research progress and applications of high - frequency ultrasound and its advanced technologies in detecting Delphian lymph node metastasis in papillary thyroid carcinoma.