Since oil-removing materials are prone to be fouled by viscous oils, causing the loss of their separation performance, water-removing textile-based materials were developed for oil/water separation with high water flux, easy-cleaning ability, and long-term efficiency in this study. Three types of highly hydrophilic and underwater oleophobic fabrics with different pore morphologies and sizes were obtained by poly(vinyl alcohol) (PVA) crosslinking. Due to the special wettability, highly porous structure, and good softness, the PVA-modified textiles served as a great filtration material for oil/water mixtures and the separation efficiency achieved above 99 %. The low-fouling performance ensured the textiles being easily cleaned and keeping high separation efficiency after using for 10 times. Factors affecting the oil/water separation performance were studied, and it was found that the separation efficiency was essentially determined by surface underwater oleophobicity and mean pore size. This study provided a fundamental understanding of the design and fabrication principle of oil/water separation materials.