Objective To investigate the factors affecting the number of lymph nodes obtained by unilateral lobectomy and isthmus combined with prophylactic ipsilateral central lymph node dissection for papillary thyroid cancer， and to analyze the pattern of change so as to provide an important basis for clinical treatment of papillary thyroid cancer. Methods Retrospective analysis was performed on the clinical and pathological data of 193 patients admitted to the department of Thyroid Surgery of the First Affiliated Hospital of Jinzhou Medical University from January 2019 to January 2022 for papillary thyroid cancer who underwent unilateral glandular lobe and isthmus resection combined with prophylactic ipsilateral central lymph node dissection. The number of obtained lymph nodes was divided into a group with high number of obtained lymph nodes（n > 6）and a group with low number of obtained lymph nodes（n ≤ 6）. Univariate analysis and multivariate analysis were used to explore the factors affecting the number of obtained lymph nodes. The influence of the number of lymph nodes on the central lymph node metastasis was evaluated by correlation analysis， and the influence of the number of lymph nodes on the quality of life of patients by postoperative complications analysis. Results The number of lymph nodes obtained was positively correlated with the number of lymph node metastases in the central region（r = 0.240，P < 0.05）and the rate of lymph node metastasis（r = 0.161，P < 0.05）， respectively. The number of lymph node metastases controlled remained unchanged，and the rate of lymph node metastasis decreased with the increase of the number of obtained lymph nodes（r = -0.444，P < 0.05）. Univariate analysis of the number of lymph nodes between the two groups showed no significant differences in terms of sex， age， operation duration， BMI， maximum tumor diameter， multifocality， Hashimoto′s thyroiditis， focal location， capsular invasion， contralateral thyroid nodule， parathyroid transplantation and BRAF gene V600E mutation（P > 0.05）. There was statistical significance in the application of nano carbon between the two groups（P < 0.05）. Logistic binary regression analysis showed that the combination of Hashimoto′s thyroiditis and the application of carbon nanoparticles were independent influencing factors for the high number of lymph nodes obtained（P < 0.05）. ROC curve analysis suggested that the area under the curve occupied by carbon nanoscale was 0.658（95%CI：0.580 ~ 0.735， P < 0.05）， and the area under the curve occupied by Hashimoto′s thyroiditis was 0.584（95%CI：0.504 ~ 0.665，P < 0.05）. In addition， there was no significant difference in the incidence of vocal cord paralysis and lymphatic leakage between the two groups （P > 0.05）. Conclusions When the number of lymph nodes in the central region remained unchanged， the higher the number of lymph nodes obtained， the lower the rate of lymph node metastasis. The application of nano?carbon and patients with Hashimoto′s thyroiditis could increase the number of lymph nodes obtained， and there is no significant difference in the incidence of postoperative complications between high and low number of lymph nodes obtained.