Objective To investigate the clinical value of thyroid iodine uptake rate, thyroid function and residual thyroid 131I maximum count (maxcount) in the evaluation of lymph node metastasis in patients with moderate to low-risk differentiated thyroid cancer under postoperative stimulation. Methods A total of 182 patients with differentiated thyroid cancer (DTC) who were admitted to our hospital from January 2016 to December 2018 after surgery with complete clinical data and wanted to receive 131I treatment were randomly selected. Thyroid iodine uptake rate, thyroid function, neck ultrasound, 131I whole body scan and neck SPECT/CT tomography were collected. Cervical lymph node metastasis was determined by postoperative pathology, cervical ultrasound, cervical SPECT/CT imaging and clinical follow-up. The correlation factors of thyroid iodine uptake rate, function and 131I maximum count in diagnosis of lymph node metastasis were analyzed.Results The results of binary logistic regression analysis showed that the cervical lymph node metastasis of middle and low-risk differentiated thyroid cancer was related to the iodine uptake rate (P=0.048), Tg (P=0.048) and maxcount (P=0.049) under postoperative stimulation, but not to TSH (P=0.256), FT3 (P=0.516), FT4 (P=0.827), TgAb (P=0.351) and TPOAb (P=0.389). ROC was applied to treat the metastasis with iodine uptake rate, Tg and maxcount. Among the three, iodine uptake rate had the highest diagnostic efficacy and maxcount had the worst efficacy. The critical values of iodine uptake rate and Tg were 1.5 and 5.28 respectively, which were statistically significant for the evaluation of lymph node metastasis. The critical value of maxcount was 727, but not statistically significant. Partial correlation analysis showed that iodine uptake rate, TSH, FT3, FT4 and TgAb were all related to maxcount, in which iodine uptake rate, FT3 and FT4 were in direct proportion to maxcount, and TSH and TgAb were in negative correlation with maxcount. Conclusion Iodine uptake rate, Tg and 131I maxcount have certain predictive value for lymph node metastasis. The higher the iodine uptake rate, FT3 and FT4, the higher the maxcount. The higher the TSH and TgAb values, the lower the corresponding maxcount level