This study aimed to investigate the effect of neuropilin-1 (NRP-1) silencing on epithelial-mesenchymal transformation (EMT) mediated by transforming growth factor-β1 (TGF-β1) and on the proliferation and migration of colon cancer SW480 cells. After transfection of small interfering ribonucleic acid (siRNA)-NRP-1 into colon cancer SW480 cells, the messenger RNA (mRNA) and protein expression levels of NRP-1 were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Four EMT models were induced using 0, 2, 5, and 10 ng/mL TGF-β1, respectively. Cell proliferation was detected using Cell Counting Kit-8, and the protein levels of EMT markers E-cadherin and vimentin were detected using Western blot. EMT was induced in the transfected SW480 cells using TGF-β1, after which four groups were created: a negative control group (siRNA-Ncontrol), a transfection group (siRNA-NRP-1), an induction group (TGF-β1), and a transfection + induction group (siRNA-NRP-1+TGF-β1). Western blot was then used to detect the expression of E-cadherin and vimentin, and cell proliferation and migration were detected using cell counting kit-8 (CCK-8) and scratch assay. After transfection with siRNA-NRP-1, the mRNA and protein expression levels of SW480 cells were significantly decreased (P<0.05). After 48 hours of induction with 10 ng/mL TGF-β1, cell proliferation was obvious, E-cadherin expression decreased, and vimentin expression significantly increased (P<0.05), indicating that EMT had been successfully induced compared with the induction group, the transfection + induction group had significantly increased E-cadherin expression after corresponding treatments (including transfection and induction alone) (P<0.05), and the proliferation and migration of colon cancer cells decreased (P<0.05). In conclusion: silencing, NRP-1 in colon cancer SW480 cells can partially reverse TGF-β1-mediated EMT, reduce the proliferation activity of colon cancer cells, and slow their migration ability. Therefore, NRP-1 may become a new target for the treatment of colon cancer.