The detection rate of thyroid cancer (PTC) has increased rapidly in recent years. Except undifferentiated cancer, surgery is still one of the most important treatments for all types of thyroid cancer, and there is a consensus to use the lobes of the gland as the minimum extent of resection. In the meantime, a basic consensus has been reached that central zone lymph node (VI) dissection is the minimum extent of lymph node dissection. In clinical practice, neck surgery and lumpectomy are mostly performed. Hypoparathyroidism and recurrent laryngeal nerve injury are the most common complications of radical surgery for thyroid cancer, both in open surgery and the luminal approach. Once these complications occur, they have a serious impact on the quality of life of patients in the postoperative period. A number of contrast agents are now being used to help minimize complications. Carbon nanoparticles are an effective and non-harmful negative developer, and many studies have confirmed that carbon nanoparticles can be used to identify parathyroid glands in thyroid surgery. Intraoperative injection of nanocarbon is effective in increasing the quality of intraoperative parathyroid detection and lymph node clearance and reducing adverse effects, such as postoperative hypokalemia.However, there is no complete clinical guideline for preoperative intraglandular injection of carbon nanoparticles, and there is no standardized dosage for appropriate injection time, injection dose, and injection method. At the same time, there is still the problem of carbon nanoparticle leakage. At our medical center, we have found that preoperative injection of carbon nanoparticles via ultrasound-guided fine needle puncture may yield better results by reducing CNS exudation in the surgical area. In this study, we will collect more than 400 patients who underwent thyroidectomy in 2025 and underwent carbon nanoparticle injections at different time points and analyzed their intraoperative and postoperative conditions as a basis for analyzing the difference in patient benefits between preoperative and intraoperative carbon nanoparticle injections and to provide data to support the clinical use of carbon nanoparticles.