Selecting several varieties of polyolefins and polyamides with corrosion resistance, temperature resistance, and aging resistance as the base material, mixed with hydrophilic, adsorptive, and anti-thermal oxidation additives, utilizing a special drawing and sliver spinning technique, the slivers are interwoven with a corrosion-resistant, high-strength core rope. Due to the refined material selection and process formula, the slivers are moderately flexible and rigid, forming a three-dimensional, uniform radiation arrangement. This creates individual suspended three-dimensional elastic filling materials. The filling material can uniformly expand and cover the entire effective area, allowing for thorough mixing and contact exchange between air, water, and biofilms. The biofilm can uniformly adhere to each sliver, maintaining good activity and porosity variability, and can also achieve a large specific surface area during operation.