Abstract:【Objective】To study the effect of nano-carbon tracer on radical operation of thyroid cancer. 【Methods】 A total of 120 patients underwent radical operation of thyroid cancer in our hospital were selected as study subjects and were divided into the nano-carbon group and the routine group, 60 cases in each group. The routine group were treated with traditional radical operation of thyroid cancer and bilateral central lymph node dissection. The nano-carbon group were injected with Carbon Nanoparticles Suspension Injection before operation, after the full development, the same operation was performed. The operation situation and effect of the two groups were compared.【Results】The number of dissected lymph nodes, levels of postoperative serum parathyroid hormone and blood calcium in the nano-carbon group [(8.19±1.77), (23.43±7.52) ng/L, (2.25±0.33) mmol/L] were significantly higher than those in the routine group [(5.38±1.92), (16.56±6.38) ng/L, (1.92±0.24) mmol/L], the difference was significant (P<0.05). The rate of remove parathyroid gland mistakenly and the incidence of postoperative complications in the nano-carbon group (8.3%, 16.7%) were significantly lower than those in the routine group (21.7%, 36.7%) (P<0.05). 【Conclusion】Nano-carbon tracer has the advantages of rapid onset, high safety and long residence time, which can improve the effect of lymph node dissection, and has good identification and protective effect on parathyroid glands.