Objective：This study aims to explore the function of miR-590-3p in papillary thyroid cancer（PTC）. Methods：We examined the miR-590-3p expression in human PTC tissues and cell lines by RT-PCR. CCK-8，EdU，wound healing，Transwell，flow cytometry were performed to analyze PTC cell function. Changes of epithelial-mesenchymal transition（EMT）signaling proteins were detected by Western blot. Results：The expression of miR-590-3p was decreased in PTC tissues and cell lines. Compared with the normal control，knockdown of miR-590-3p promoted cell proliferation，migration，invasion and inhibited cell apoptosis in PTC cells（P < 0.01）. However，overexpression of miR-590-3p inhibited cell proliferation，migration，invasion and promoted cell apoptosis in PTC cells（P < 0.01）. And miR-590-3p significantly inhibited EMT process. Conclusion：MiR-590-3p acts as a tumor suppressor in PTC carcinogenesis and metastasis，and may be a therapeutic target for PTC.