Objective To investigate the effect of resveratrol (RSV) on epithelial-mesenchymal transition of MDA-MB-231 cells by down-regulating POLD1 expression. Methods CCK-8 was used to detect the effect of RSV on the activity of MDA-MB-231 cells. POLD1-OE and POLD1-NC cell lines were constructed by transfecting MDA-MB-231 cells with recombinant lentivirus. Western blot was used to detect the expression of POLD1, E-cadherin, N-cadherin and Vimentin after RSV treatment. Transwell invasion experiment and the scratch test were used to detect the cells invasion and migration abilities of each experimental group. Results RSV could significantly inhibit the survival of MDA-MB-231 cells, reduce the expression of POLD1, N-cadherin and Vimentin, increase the expression of E-cadherin, and inhibit the abilities of cell invasion and migration. Increasing the POLD1 expression could reduce the above-mentioned biological effects of RSV on MDA-MB-231 cells. Conclusion RSV could significantly inhibit the viability and EMT of MDA-MB-231 cells by down-regulating the expression of POLD1.