Inspired by soft coral's self-cleaning properties, a polyrotaxane-based membrane (EVOH-PR) with sliding α-cyclodextrin rings was designed to enhance flux and antifouling performance. The sliding-ring structure, synthesized via click chemistry, mimics coral's dynamic motion to induce hydration layers and steric hindrance. Molecular dynamics simulations confirmed the dynamic behavior of PR and the dynamic antifouling mechanism. The EVOH-PR membrane achieved a high flux recovery rate (95.1%), low flux decline rate (7.54%), and maximum flux (720 L/(m2·h)). Stability tests showed unchanged hydrophilicity and separation efficiency after multiple cycles. Synergy between movable rings, hydration layers, and steric hindrance enabled dynamic antifouling. This work provides a proactive dynamic antifouling strategy through coral-inspired molecular motion.