Deep efficient purification method for water body

The invention discloses a deep efficient purification method of a water body. A polluted water body is sequentially subjected to coagulation, coagulation aiding, precipitation, plasma denitrification treatment, adsorption phosphorus removal and phosphorus precipitation recovery through a coagulation precipitation device, a plasma denitrification device and an adsorption phosphorus removal and phosphorus recovery device. The deep efficient purification method for the water body is high in adsorption phosphorus removal capacity, the total phosphorus in the water body is smaller than or equal to 0.1 mg/L, meanwhile, COD and chromaticity in the water body are adsorbed, the water quality is further improved, the COD in the water body can be removed by 80%-95% after adsorption phosphorus removal, the COD of effluent is smaller than or equal to 20 mg/L, and the BOD of the effluent is smaller than or equal to 6 mg/L; 95-99% of total phosphorus is removed, so that the total phosphorus of effluent is less than or equal