NOVELTY - A denitrification of industrial cultivation waste water comprises enriching and acclimatizing heterotrophic nitrobacteria and oceanic heterotrophic nitrobacteria in container separately, adding oceanic cultivation waste water in the container, adjusting pH and salinity of mixture, enriching and acclimatizing the mixture by adding ammonium chloride, acclimatizing the mixture, separating oceanic heterotrophic nitrobacteria and amplification-culture, and expanding heterotrophic nitrobacteria with strong nitrification ability by the solid and liquid mode.    USE - Method for denitrification of industrial cultivation waste water (claimed) used for decomposing and converting NH3-N2 and nitrite N2 and organism that are harmful to the biology.    ADVANTAGE - The method reduces the N2 content of cultivation water body to reduce the pollution of environment around the cultivation place. The method requires less investment, simple operation, and high efficiency.    DETAILED DESCRIPTION - A denitrification of industrial cultivation waste water comprises enriching and acclimatizing heterotrophic nitrobacteria and oceanic heterotrophic nitrobacteria in the container separately, adding oceanic cultivation waste water in the container, adjusting pH to 7.5-8.5 using sodium carbonate (Na2CO3) solution, adjusting salinity to 1.020, controlling temperature of waste water to 23-27 degrees C, adjusting chemical oxygen demand (COD) of wastewater to 5-50 mg/L, enriching and acclimatizing the mixture by adding ammonium chloride (NH4Cl) (0.2-2 g/L) each day, acclimatizing the mixture for 20-30 days, separating heterotrophic nitrobacteria from acclimatizing liquid if there is loss of the whole nitrogen (N2) measured as organic N2, separating oceanic heterotrophic nitrobacteria and amplification-culture, using solid organic culture medium prepared by seawater to separating oceanic heterotrophic nitrobacteria, coating the diluted liquid of the enriching and acclimatizing liquid on the organic culture medium to culture for 3 days at 23-27 degrees C, drawing and purifying colonies with the different characteristics in the culture medium, measuring the nitrification ability of single strain until obtaining oceanic heterotrophic nitrobacteria, expanding heterotrophic nitrobacteria with strong nitrification ability by the solid and liquid mode, absorbing and fixing oceanic heterotrophic nitrobacteria, adding the amplification-cultured oceanic heterotrophic nitrobacteria liquid and multiple pore carriers into triangular flask, controlling the temperature at 22-27 degrees C at 80-150 rpm, absorbing and allowing the mixture to stand for 48 hours, placing the carriers fixed by shaking table into the biological reactor to reflow and absorb the mixture for 24 hours using the same nitrobacteria liquid, reacting the mixture for 1-2 hours, using upper flow mode and submerging the whole water body to establish upper-flow submerging biological reactor, implementing biological denitrification of industrial cultivation wastewater, changing all factors (such as concentration of ammonia (NH3)-N2 at 0.2-0.8 mg/L) after the carrier in the upper flow submerging biological reactor absorbs the oceanic heterotrophic nitrobacteria, staying the product in water for 15-150 minutes, at COD of 5-20 mg/L and for 12-48 hours, and measuring denitrification efficiency of the upper flow submerging biological reactor and when dentrification efficiency reaches greater than 50% within 1 hour, it indicates that the denitrification of industrial cultivation wastewater is established. The number of the nitrobacteria is greater than 108/ml. The volume of waste water is 3/4 of the volume of the container. The oxygen solubility of waste water is greater than 3 mg/L.