Selecting several varieties of polyolefins and polyamides that are resistant to corrosion, temperature, and aging, the elastic filling screen is mixed with hydrophilic, adsorption, and heat-resistant oxidant additives. It employs a special spinning and sliver yarn fluffy technique, intertwining the yarns with a durable, high-strength central rope. Due to the careful selection of materials and precise formulation, the yarns are arranged in a three-dimensional, even, radiating pattern, creating individual suspended three-dimensional elastic filling units. The filling material can uniformly expand and cover the effective area in a three-dimensional, omnidirectional manner, allowing for full mixing and contact exchange between air, water, and biological films. The biofilm can not only evenly adhere to each yarn while maintaining good activity and porosity variability but also achieve a large specific surface area during operation.