Objective To investigate the effect and action mechanism of Yutaro polysaccharide（YLSPS） on lipopolysaccharide（LPS）⁃induced inflammatory injury and apoptosis of human thyroid follicular epithelial cells. Methods After being treated with different concentrations of YLSPS，the LPS⁃induced human thyroid follicular epithelial cells Nthy⁃ori3⁃1 were transfected with the Caveolin⁃1 overexpressed vectors. The levels of interleukin 1 （IL⁃1），interleukin 6（IL⁃6），and monocyte（MCP⁃1）chemotactic protein 1 were measured by enzyme⁃linked immunosorbent assay，and apoptosis was measured by flow cytometry. The Caveolin ⁃ 1 mRNA expression levels were measured by quantitative real ⁃time PCR（RT ⁃qPCR）and Caveolin ⁃1 protein expression was determined by protein blotting（Western Blot）. The thyroiditis model mice were treated with YLSPS and the thyroid tissues in each group were observed in view of morphologybymicroscopy. Results YLSPS reduced the levels of IL⁃1，IL⁃6 and MCP⁃1 and apoptosis（P < 0.05）in the LPS⁃induced cells，and promoted the mRNA and protein expression levels of Caveolin⁃1（P < 0.05）in the cells in a dose⁃dependent manner. Overexpressed Caveolin⁃1 also decreased the levels of IL⁃1，IL⁃6，and MCP⁃1 and the rate of apoptosis in the Nthy⁃ori3⁃1 cells.YLSPS improved the thyroid tissue in morphology，reduced IL⁃1，IL⁃6，and MCP⁃1 levels in the mouse serum，and promoted Caveolin⁃1 pro⁃ tein expression in the thyroid tissues. Conclusion YLSPS can inhibit the inflammatory damage and apoptosis in Nthy⁃ori3⁃1 cells，and its mechanism of action is related to the upregulation of Caveolin⁃1 expression.