Objective To investigate the efficacy of fine needle aspiration-thyroglobulin (FNA-Tg) with colloidal gold immunochromatographic assay (CGICA) on the assessment of lymph node metastasis during surgery in papillary thyroid carcinoma (PTC) patients. Methods Seventy-eight patients with PTC who underwent surgery in the Department of Thyroid Surgery of West China Hospital of Sichuan University from August to December 2019 were selected as the research objects, 289 neck lymph node specimens cleaned during the operation were prepared into eluent after lymph node FNA within 10 minutes in vitro, and then the FNA-Tg level was detected rapidly and quantitatively by CGICA. The specimen of washout fluid was labeled and sent to the laboratory for FNA-Tg detection by Roche electrochemiluminescence immunoassay. The lymph nodes in the whole group were divided into central region group and lateral cervical region group according to their location. According to the long diameter of lymph nodes, they were divided into <5 mm group, 5–10 mm group and >10 mm group. With postoperative pathological report as the gold standard, the receiver operating characteristic (ROC) curve of the whole group of data subjects was drawn, and the area under curve (AUC) was compared to calculate the best cut-off value of FNA-Tg in diagnosing PTC lymph node metastasis. The sensitivity, specificity, diagnostic accuracy, positive predictive value and negative predictive value of FNA-Tg CGICA method and Roche method in the whole group and different subgroups were compared. The data of 55 lymph nodes detected by FNA-Tg CGICA method and rapid frozen pathology were collected, and the diagnostic efficacy indexes of CGICA method and rapid frozen pathology in the diagnosis of lymph node metastasis were compared. Results The ROC curves AUC of FNA-Tg detected by CGICA method and Roche method was 0.850 and 0.883, respectively, the difference was not statistically significant (Z=1.011, P>0.05). The sensitivity was 77.7% and 79.6% respectively (χ2=0.05, P>0.05), specificity was 84.9% and 93.5% respectively (χ2=7.50, P<0.05). Using McNemar test, there was no significant difference in the diagnostic results between the CGICA method and Roche method of FNA-Tg in the whole group (P>0.05). The diagnostic efficacy of FNA-Tg CGICA method was better in the lateral cervical region group than that in the central region group, and the diagnostic efficacy of the group with the long diameter of lymph nodes >10 mm was better than those of the groups with the long diameter of lymph nodes <5 mm and 5–10 mm. There was no significant difference in diagnostic results between FNA-Tg CGICA method and rapid frozen pathology (P>0.05). Conclusions The FNA-Tg CGICA method has high value in diagnosing PTC cervical lymph node metastasis, and has the characteristics of rapidity and convenience. The diagnostic efficiency is similar to that of Roche method.