Objective：We aimed to explore the relationship between thyroid autoantibodies and anti -GM1 antibody in Guillain-Barré syndrome（GBS）patients. Methods：We selected 60 GBS patients who were admitted to Nanjing Drum Tower Hospital from July 2018 to February 2023 and tested for both anti-thyroid antibodies and Antiganglioside antibody（AGA）levels. According to anti-thyroid antibodies，the patients were divided into normal group and abnormal group. The clinical characteristics，thyroid function and the proportion of AGA in the two groups were compared. Results：Compared with the normal group，GBS patients in the abnormal group had significantly increased anti -GM1 antibody（Ab）（P < 0.05）and anti -GM2 Ab（P < 0.05），and were accompanied by more severe clinical symptoms（P < 0.05）. Multivariate logistic regression analysis showed that the presence of abnormal anti-thyroid antibodies［OR=5.184，95%CI：1.377-19.518，P=0.015］and increased free thyroxine（FT4）levels［OR=1.266，95%CI：1.009-1.588， P=0.030］ were independent risk factors for increased anti-GM1 antibody positive rate in GBS patients. Receiver operation characteristic（ROC）curve analysis found that the optimal threshold for thyroperoxidase antibody（TPO -Ab）to predict anti -GM1 Ab positive was 47.9 U/mL，with a sensitivity of 66.7% and a specificity of 77.8%. The optimal threshold for thyroglobulin antibody（Tg-Ab） to predict anti-GM1 Ab positive was 20.0 U/mL，with a sensitivity of 73.3% and a specificity of 73.3% . Conclusion：Our results suggest an association between thyroid autoantibodies and anti-GM1 antibody in GBS patients，potentially explaining the poorer prognosis of GBS patients with thyroid dysfunction.