NOVELTY - High density aquaculture sewage processing method comprises pumping sewage into microbial flocculation reactor; adding Bacillus subtilis seed bacteria liquid; aerating, adding bio-flocculating agent and decomposing organic matter; flowing mixed butyraldehyde and catalyst to biotreatment reactor, filling biofilter material, carrying out solid-liquid separation, discharging suspended sludge part; and reflowing sludge to flocculation reactor, refluxing, separating clear liquid, degrading organic substance, stopping reaction, and returning purified water to culture pond.    USE - Method for processing high density aquaculture sewage.    DETAILED DESCRIPTION - High density aquaculture sewage processing method comprises: (A) pumping high density aquiculture sewage into microbial flocculation reactor; adding B. subtilis seed bacteria liquid after activating culture, where seed liquid cultivating wastewater volume ratio is 1-3: 100; uniformly providing aeration device in reactor bottom, where gas-water ratio is 2-2.5: 1, and dissolved oxygen concentration is 2-3 mg/L; putting seed bacteria liquid in suspension state by blast aeration effect, adding bio-flocculating agent, and decomposing organic matter for 0.8-1.2 hours; (B) flowing mixed butyraldehyde and catalyst generated by liquid to deposition-biotreatment reactor, providing natural ventilation for oxygen, filling suspended biofilter material at filling rate of 25-30%, carrying out solid-liquid separation and mixed solution biochemical reaction, generating deposit, removing sludge part and discharging together; and (C) reflowing sludge to microorganism flocculation reactor, refluxing at a ratio of 30-40%, separating the clear liquid at upper layer, conducting suspension biofilter function capable of further degrading organic substance, stopping the reaction after 0.8-1 hour, and returning purified water to culture pond.    DESCRIPTION OF DRAWING(S) - The drawing is a block diagram of high density aquaculture sewage processing method (Drawing includes non-English language text).