This study evaluates the clinical significance of nano-carbon suspension in total thyroidectomy with cervical lymph node dissection for papillary thyroid carcinoma (PTC). The objective of this study was to assess the efficacy of nano-carbon suspension in enhancing parathyroid gland preservation, reducing postoperative complications, and improving surgical precision. A retrospective analysis on 219 PTC patients who underwent total thyroidectomy with cervical lymph node dissection between March 2014 and March 2018 was conducted. Patients were divided into two groups: an experimental group (n = 107) that received nano-carbon suspension and a control group (n = 112) that did not. Comparative analyses included demographics, surgical parameters, postoperative calcium and parathyroid hormone (PTH) levels, the number of dissected lymph nodes, and the incidence of complications. Baseline characteristics, including age, sex, and BMI, showed no statistically significant differences between the experimental and control groups. Postoperative calcium levels were significantly more stable in the experimental group, with median levels of 2.22 mmol/L on day 1 versus 2.06 mmol/L in the control group (P < 0.001), and 2.29 mmol/L at week 1 versus 2.22 mmol/L (P < 0.001). PTH levels were higher in the experimental group (35 pg/mL on day 1 versus 28 pg/mL, P < 0.001; 37 pg/mL at week 1 versus 30 pg/mL, P < 0.001). The experimental group had a greater median number of dissected lymph nodes (median 11.00 versus 7.00, P < 0.001) and a lower pathological parathyroid gland count (6.5% versus 23.2%, P < 0.001). Postoperative numbness and twitching were significantly reduced (4.7% versus 16.1%, P = 0.006), and the recurrence rate at 12 months was lower (4.7% versus 12.5%, P = 0.040). The use of Nano-carbon suspension in thyroidectomy and cervical lymph node dissection for PTC enhances parathyroid gland preservation, improves surgical precision, and reduces specific postoperative complications, supporting its standard adoption in thyroid cancer surgeries to optimize patient outcomes.