TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Method: The step (a) is performed by collecting oil polluted water sample from oil well which is 800-1000 m deep at 26-30 degrees C, removing impurities and uniformly mixing the polluted water sample and transferring the mixed sample to a triangular flask with inorganic culture medium, shaking and culturing bacteria for 7 days at 30 degrees C in a shaker before culturing the culture in the fresh inorganic culture medium, obtaining enriched nutrient, inoculating the enriched nutrient in an enriching culture medium, culturing for 7 days at 30 degrees C, adding the culture obtained culture to the fresh enriching culture medium before repetitively culturing for 7 days at 30 degrees C, adding the obtained culture to the fresh enriching culture medium, repetitively culturing for 7 days at 30 degrees C, obtaining domesticating culture liquid, and dipping the domesticating culture liquid in aseptic condition. The culture liquid is lined on a flat slab of an oily inorganic culture medium, inverting the flat slab, and culturing for 24 hours at 30 degrees C in the constant temperature culture box, obtaining typical bacterial colony, repetitively lining the typical bacterial colony on the flat slab of the separating culture medium, obtaining single bacterial colony, respectively inoculating the strain of the single bacterial colony to the oblique culture medium and storing in refrigerator. The method involves testing the crude oil degrading rate of the strain of the single bacterial colony, identifying the bacteria type having degrading rate of 70% by 16 nuclear small subunit ribosomal DNA (SrDNA) molecules method. The combined bacterial solution is prepared by inoculating the strain belonging to Pseudomonas, Flavobacterium, and Corynebacterium into the seed culture medium, carrying out intermediate culture for 24 hours at 30 degrees C, respectively absorbing 100 millions to 100 billion/1 ml of strain suspension with Pseudomonas, 100 millions to 100 billion/20 ml of strain suspension with Flavobacterium, and 100 millions to 100 billion/1 ml of strain suspension with Corynebacterium and mixing various bacterial solutions. Preferred Components: The inorganic culture medium comprises (in g) mixture of dipotassium hydrogen phosphate, anhydrous (1), magnesium sulfate heptahydrate (0.5), ammonium nitrate (1), calcium chloride (0.02), ferric chloride (0.03), and deionized water (1 l) at pH of 7.5. The enriching culture medium comprises mixture of inorganic culture medium and 2 g of crude oil phase at pH of 7-7.5. The oily inorganic culture medium comprises mixture of inorganic culture medium, 2 g of crude oil, and 20 g of agar. The seed culture medium comprises (in g) glucose (20), peptone (5), yeast extract (3), sodium chloride (5), distilled water (1 l) at pH of 7.5. The degrading liquid culture medium comprises inorganic culture medium and 1g of crude oil. The method involves inoculating the combined bacteria solution into the biological reactor with oil polluted water sewage (3%) to be processed, adding (in g/l) magnesium sulfate (2), copper sulfate (0.5), manganese sulfate (0.5), ferrous sulfate heptahydrate (0.5) and calcium hypochlorite (0.5), and regulating the rotating speed of the reactor at 110-150 rpm at 28-30 degrees C at the ventilating amount of 0.002-0.008 m/s.