Abstract: Using the graft copolymerization method, two types of terminally hydroxy-functionalized silicone oils (Silok-8822F2 and Silok–8866) were introduced into polyurethane (PU) chains to prepare two series of silicon-modified waterborne polyurethanes (PU1 and PU2). The structure and properties of the materials were characterized by using Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, contact angle measurements, and mechanical performance tests. Results demonstrated that the grafting copolymerization reactions successfully introduced polydimethylsiloxane (PDMS) segments into the polyurethane matrix, and these PDMS segments were enriched on the polyurethane surface to form a concave-convex structure, enabling the silicon-modified polyurethanes to possess dynamic amphiphobicity. Furthermore, after the commercial synthetic leather was treated with the silicon-modified polyurethane emulsions, its surface exhibited dynamic amphiphobic properties, indicating the potential of these emulsions to serve as effective surface treatment agents for enhancing the surface performance of synthetic leather.