Biological treatment method of circulating culture water body

The invention provides a biological treatment method of circulating culture water body. A porous suspension filling material and shell filling material are used in the method. The method comprises a movable bed biological filter tank treatment and an immersed form biological filter tank treatment. The pollutants in water body is oxidized and degraded by the biomembrane arranged in a movable bed biological filter tank, the main pollutants of the water body can be eliminated, part of particles are retained through the biological flocculation, then the water body is introduced into an immerse form biological filter tank composed of a shell filling material, the main component of the shell filling material is calcium carbonate, which can balance the pH value, and moreover, the biological membrane on the surface of the shell filling material can further purify the water. Compared with the conventional biological processing technology, the advantage of efficiently eliminating soluble pollutants of a movable bed biological filter tank is preserved, at the same time the shell filling material of an immerse form biological filter tank is fully utilized to balance the pH value of the culture water body, the utilization rate of culture water body is increased, and the cost for adjusting the pH value is reduced.