The invention discloses a preparation method of a novel biological deodorization bacterium agent. The preparation method comprises the following steps: a, selecting strains: selecting the following microorganism strains according to a weight ratio: saccharomycetes, bacillus subtilis, bacillus licheniformis, lactobacillus plantarum and bacillus megaterium; b, carrying out primary culture; c, carrying out secondary culture; d, uniformly mixing; e, freezing and drying in vacuum; f, selecting 300 to 320 parts of activated carbon, 250 to 280 parts of diatomite and 230 to 270 parts of zeolite according to a weight part ratio; crushing until the granularity is 26 to 35 meshes; sufficiently and uniformly mixing with solid-state bacterium powder to prepare the novel biological deodorization bacterium agent. The preparation method disclosed by the invention has the advantages that organic matters, which emit an undesirable odor, are composted and fermented through a microorganism strain, and substances, which emit the undesirable odor, are transformed into odorless substances, so that the source of the undesirable odor is solved radically and a very good deodorization and purification effectis realized; the novel biological deodorization bacterium agent has no pollution to the environment, no residues of chemical substances and is very environmentally friendly.