Abstract： Surgery is the important treatment for each type of thyroid cancer. Single or multiple parathyroid injuries or blood supply disorders may occur during the operation, resulting in dramatic decline of parathyroid hormone and hypocalcemia after operation, which is common in clinical practice. After discharge, chronic hypocalcemia can cause great physical and psychological pain to patients. Although the residual parathyroid glands can compensate after surgery in some cases, long-term negative calcium balance and postoperative hypocalcemia may cause excessive hyperplasia of the residual parathyroid glands, resulting in parathyroid hyperfunction or even hyperparathyroidism, which can lead to osteoporosis, urinary calculi, metastatic vascular calcification, and systemic abnormal migratory calcium deposits. It’s advisable to enhance the awareness of the cause and harm of the postoperative hypocalcemia, evaluate and diagnose it early, and actively intervene in every stage of before, during and after the operation and long-term follow-up, which can effectively reduce the occurrence and severity of hypocalcemia and improve the postoperative life quality and the prognosis.