172 patients with benign thyroid nodules and 285 patients with malignant nodules diagnosed in the Second People's Hospital of Liaocheng from January 2017 to October 2019 were selected as the research objects， and 199 patients with health examinations in the hospital during the same period were selected as the control group， the preoperative peripheral blood neutrophil count， lymphocyte count and platelet count were recorded， and NLR， PLR and SII were calculated， and NLR， PLR and SII in healthy people， benign nodules， and malignant nodules were compared by t test for the difference between groups， the receiver operating characteristic curve （ROC curve） was used to determine the critical values of NLR， PLR， and SII in different groups.

Except that there was no statistically significant difference between NLR and SII in the comparison of benign and malignant nodules （group A vs group B）， the three indicators （NLR， PLR， SII） in the other three groups were compared with each other， and the differences were statistically significant （P < 0.05）. The area of AUC was between 0.72 and 0.8. The sensitivity of NLR， PLR， and SII in the identification of healthy people and benign thyroid nodules was 85.9%， 92.5%， and 81.9% respectively. In the detection of healthy people and malignant thyroid nodules， the sensitivity in the discrimination was 70.4%， 81.9%， and 74.1%， respectively. The discrimination specificities in the benign nodule group and the malignant nodule group were 85.6%， 69.5%， and 83.2%， respectively， and the significance was significant.

The detection of NLR， PLR， and SII has a certain value to distinguish between healthy people and benign nodules and healthy people and thyroid nodules， but it is not significant to distinguish between benign and malignant nodules.