NOVELTY - Preparing immobilized cold resisting nitrobacteria comprises locating the sludge in the secondary clarification of the spring sewage processing factory in the low temperature biochemical incubator, cultivating, adding domestic sewage, and using the nitrobacteria domestication culture medium for replacing some portion of the domestic sewage, reducing the temperature of the incubator to obtain the low temperature resisting nitrobacteria flora; vaccinating the nitrobacteria flora to the nitrobacteria liquid culture medium; and fixing to obtain the immobilized cold resisting nitrobacteria.    USE - Method for preparing immobilized cold resisting nitrobacteria (claimed).    ADVANTAGE - In the method, the growth of the nitrobacteria is stable at low temperature, the generation time is short, and the eliminating efficiency for the ammonia and nitrogen in the sewage is high.    DETAILED DESCRIPTION - Preparing immobilized cold resisting nitrobacteria comprises:    (A) locating the sludge in the secondary clarification of the spring sewage processing factory in the low temperature biochemical incubator at 14-16 degrees C, cultivating in the condition that the sludge is 2-3 g/L, the dissolved oxygen is 2-3 mg/L, obtaining the domestication sewage every 2-3 days, keeping statically for 25-35 minutes before replacing the domestic sewage and removing the upper clean liquid for 0.67, adding the domestic sewage having the same volume with the removed upper clean liquid; after obtaining the domestic sewage for 2-3 times and using the nitrobacteria domestication culture medium for replacing some portion of the domestic sewage for cultivating for 20-26 days, reducing the temperature of the low temperature biochemical incubator at 11-13 degrees C and working for 20 days, reducing to 9-10 degrees C and working for 20 days to obtain the low temperature resisting nitrobacteria flora;    (B) vaccinating the low temperature resisting nitrobacteria flora to the nitrobacteria liquid culture medium having a pH of 7-8, cultivating for 15-20 days at 12-15 degrees C and 80-100 revolutions/minute, the dissolved oxygen is 1:1, and obtaining the cold resisting nitrobacteria flora; and    (C) preparing the cold resisting nitrobacteria flora cultivating liquid (4-6 mass%) obtained in step (B) into the suspension solution, mixing with the low temperature resisting nitrobacteria flora solution in a volume ratio of 1:10 and using the combined type fiber filler for forming the film and fixing, working for 14-16 days after adding the combined type fiber filler at the condition that sludge is 2-3 g/L, the dissolved oxygen is 2-3 mg/L, when the attached biomass on the combined type fiber filler is 2 g/L, obtaining the immobilized cold resisting nitrobacteria; the low temperature resisting nitrobacteria flora solution in step (C) is prepared by the low temperature resisting nitrobacteria flora obtained in step (A); the low temperature resisting nitrobacteria flora is present at 4-6%; the nitrobacteria domestication culture medium in step (A) is used for replacing the domestic sewage and the replacing interval is 2-3 days; the nitrobacteria domestication culture medium in 10 vol.% of the upper clean liquid is used for replacing the domestic sewage at the first time, the nitrobacteria domestication culture medium in 30 vol.% of the upper clean liquid is used for replacing the domestic sewage at the second time, the nitrobacteria domestication culture medium in 50 vol.% of the upper clean liquid is used for replacing the domestic sewage at the third time, the nitrobacteria domestication culture medium in a 70 vol.% of the upper clean liquid is used for replacing the domestic sewage at the third time, and the nitrobacteria domestication culture medium in a 70 vol.% of the upper clean liquid is used for replacing the domestic sewage.