Composite fillers are developed on the basis of soft fillers and semi soft fillers, and have the advantages of both. Composed of fiber bundles, plastic rings, sleeves, and central ropes, its structure is to change the plastic rings into double loop large plastic rings by pressing aldehyde fibers or polyester fibers onto the loops of the rings, so that the fiber bundles are evenly distributed; The inner circle is made of snowflake shaped plastic branches, which can not only hang film but also effectively cut bubbles, improving the transfer rate and utilization rate of oxygen. Ensure sufficient exchange of water vapor biofilm and efficient treatment of organic matter in water.