Background and Aims As a new lymph tracer, nanocarbons have been widely used in traditional thyroidectomy. Minimally invasive surgery is nowadays the theme of surgery. Robotic technology has spurred the development of minimally invasive surgery, and its safety and effectiveness have been widely recognized. This study was conducted to investigate the effect of using a carbon nanoparticle tracer for lymph node dissection in robotic thyroidectomy to provide a reference for clinical use.Methods The data of 294 patients with papillary thyroid carcinoma who underwent radical resection by Da Vinci robotic surgical system were retrospectively analyzed. Of the patients, carbon nanoparticle tracer was used in 160 cases (observation group) and not in 134 cases (control group) during surgery. The total number of central and lateral cervical lymph node dissections, number of positive lymph nodes, operative time for lymph node dissection, and incidence of complications of lateral cervical lymph node dissection were compared between the two groups.Results There were no significant differences in age, gender, tumor size, TNM stage, and the presence or absence of capsular invasion between the two groups (all P>0.05). In observation group versus control group, the average number of central lymph nodes dissected (13.46 vs. 8.66) and the average number of positive lymph nodes detected (3.38 vs. 2.31) were significantly higher (both P<0.05); the average number of lateral cervical lymph nodes dissected was significantly higher (15.21 vs. 1.44, P<0.05), but its average number of positive lymph nodes detected showed no significant difference (P>0.05). The operative time for unilateral central lymph node dissection (77.08 min vs. 88.83 min), bilateral central lymph node dissection (128.29 min vs.160.11 min), and for central plus lateral cervical lymph node dissection (199.93 min vs. 221.64 min) were significantly reduced in observation group compared with control group (all P<0.05). There were no significant differences in incidence rates of all specific postoperative complications following lateral cervical lymph node dissection between the two groups (all P>0.05).Conclusion The application of nanocarbon in robotic thyroid cancer surgery can significantly increase the number of lymph nodes detected, improve the detection rate of positive central lymph nodes, and shorten the operative time for neck dissection.