The invention relates to a spiral filler which comprises a middle rope and fibers fixed on the middle rope, wherein the fibers comprise a plurality of fiber units; each fiber unit is spirally wound on the middle rope to form one layer; every two adjacent fiber units are connected to form multilayer spirals; and a clearance is left between every two adjacent layers of fiber units. Due to the adoption of the spiral structure, the invention can effectively increase the specific area of the filler, improve the water and gas distribution properties of the filler, fully raise the transfer rate and utilization ratio of oxygen, and obviously enhance the biological treatment effect.