Objective To investigate the influencing factors of contralateral central lymph node (Cont-CLNs) metastasis in patients with unilateral papillary thyroid carcinoma (PTC) with ipsilateral cervical lymph node metastasis (LLNM). Methods A total of 127 LLNM-PTC patients admitted to Jiangyuan Hospital Affiliated to Jiangsu Institute of Atomic Medicine from July 2018 to July 2022 were selected and divided into metastasis group (n=68) and non-metastasis group (n=59) according to whether they had Cont-CLNs metastasis. Data of the patients were collected, including gender, age, tumor size, tumor echo, blood flow signal, microcalcification, tumor number, pathological gland lobe, nodular thyroid cyst, capsule invasion, Hashimoto′s thyroiditis, incidence of central lymph node, pretracheal lymph node and prelaryngeal lymph node metastasis and postoperative complications. Binary logistic regression model was used to analyze the factors influencing the occurrence of Cont-CLNs metastasis in LLNM-PTC patients. SPSS statistics 20.0 was used for statistical analysis. Data comparison between two groups was perfomed using t test or χ² test depending on data type.Results In the metastasis group, the proportion of male, microcalcification, multiple tumor and capsule invasion was 75.00% (51/68), 47.06% (32/68), 55.88% (38/68) and 47.06% (32/68), respectively. It was higher than that in the non-metastasis group 37.29% (22/59), 16.95% (10/59), 18.64% (11/59), 15.25% (9/59), and the maximum tumor diameter in the metastat group was greater than that in the non-metastasis group (P<0.05). The metastasis rates of central lymph nodes, pretracheal lymph nodes and prelaryngeal lymph nodes were 51.47% (35/68), 44.12% (30/68) and 50.00% (34/68), respectively. It was higher than 20.34% (12/59), 15.25% (9/59) and 16.95% (10/59) in non-metastasis group (P<0.05). Binary logistic regression analysis showed that male, tumor size, microcalcification, multiple tumors, capsule invasion, central lymph node metastasis on the affected side, pretractal lymph node metastasis, and prelaryngeal lymph node metastasis were independent risk factors for Cont-CLNs metastasis, and the difference was statistically significant(P<0.05). Conclusion The occurrence of Cont-CLNs metastasis in LLNM-PTC patients is affected by multiple factors, including gender, tumor size, microcalcification, tumor number, capsule invasion, and lymph node metastasis in the central region of the affected side, pretracheal and prelaryngeal area, which deserves attention clinically.