The prevalence of thyroid nodules has been increasing in recent years，and some studies have shown that glucose metabolic disorder may be one of the important reasons，mainly involving insulin/insulin-like growth factor 1，leptin，inflammation，genetic immunity and other mechanisms. Metformin can inhibit thyroid nodules through different signaling pathways. This article introduces the linkage between thyroid nodules and glucose metabolism disorders，and analyzes the mechanism of metformin inhibiting thyroid nodules.