Differentiated thyroid cancer (DTC) is one of the most common cancer in China. Thyroidectomy combined with radical neck dissection is still the curative therapy for patients with DTC, with low incidence of recurrence and improved prognosis. However, there are some controveries about the extent and neccessarity of either preventive or curative neck dissection in the surgical treatment of DTC. The carbon nanoparticle is a new lymph tracer with a clear lymphatic mapping and a longer time of dying. This lymphatic tracer technique could improve the dissection of central compartment lymph node lymph nodes, while protecting parathyroid gland from false resection and decreasing the incidence of RLN injury and postoperative hypocalcemia, with important clinical significance.