Waterborne polyurethane (WPU) exhibits excellent flexibility and durability; however, its dense structure limits the design of moisture/water-vapor transport pathways. Poly(vinyl alcohol) (PVA), while highly hydrophilic due to abundant hydroxyl groups and readily capable of forming hydrogen-bonding networks, suffers from excessive swelling and reduced mechanical strength under wet conditions, which restricts its practical applications. In this study, focusing on the complementary characteristics of these two polymers, effective complexation between the components was achieved via intermolecular hydrogen bonding between urethane groups (–NHCOO–) and hydroxyl groups (–OH). We further confirmed that this complexation influences the microstructure and mechanical properties of the resulting composites. This work was supported by KOITA grant funded by MSIT(KOITA20250002-18)