The invention pertains to the technical field of bio-treatment of environmental pollutants, particularly relates to a bacterium for degrading o-nitrobenzaldehyde and the applications thereof in bio-treatment of waste water and remediation of soil environmental pollution. The degrading bacterium of o-nitrobenzaldehyde is the strain ND1 of Alcaligenes sp. The bacterium can degrade o-nitrobenzaldehyde with high efficiency under aerobic condition, and utilize albocarbon, p-nitrophenol, o-nitrophenol, ortho-aminophenol, toluene, p-dimethylaminobenzaldehyde, 2, 4-dinitrophenol, para hydroxy benzoicacid, diphenylamine, benzoic acid, xylene and a plurality of other aromatic compounds. The Alcaligenes sp.ND1 is sensitive to five common antibiotics of tetracycline, kanamycin, streptomycin, chloromycetin and ampicillin, thus providing safe guarantees in the application thereof in the bio-treatment of waste water and remediation of soil environmental pollution.