Hydrogels possess characteristics of anti-protein adsorption, which have attracted significant attention in the field of ship antifouling. Traditional hydrogels often exhibit poor mechanical properties and lack long-term application value. Herein, a PEGp hydrogel for underwater antifouling applications was prepared. PEGp hydrogel demonstrates excellent water retention, elasticity, and antifouling properties. It can effectively resist the adsorption of proteins and bacteria. The long-term antifouling test shows that PEGp hydrogel has application prospects in the marine environment. Additionally, molecular dynamics (MD) simulations show that water molecules interact with the PEGp to form a hydration layer, endowing PEGp hydrogel with hydrophilicity. These studies offer a novel approach to developing ship antifouling materials and exploring new directions for environmental protection and antifouling.