In the cold area, there always exists the problem to treat low-temperature sewage in winter by bio-treatment technology, but it is difficult to reach the criterion since the low efficiency and the high difficulty. Domestic wastewater is a high concentration of oil wastewater and if it is discharged directly without treatment, it will affect the water body reoxygenation and its self-purification process, which endangers the water ecosystem. The study tried to tackle the problem from the morphology and physiology perspective of microorganisms. The sewage water samples were taken from a residential area and eight cold-adapted strains with high oil degradation capacity were isolated and at the temperature of 5°C. The bacteria were identified and determined the genus through physiological and biochemical tests and fatty acid identification system. The effect of pH value on the oil degradation rate was investigated. The results showed that the optimal culture conditions were 5°C, 7.0 of initial pH, peanut oil as carbon source. Under the conditions, the bacteria had the higher degradation capacity.