The invention relates to composite biological deodorization spray for pets and a preparation method thereof. The spray is suitable for solving the problems of halitosis, body odor, feces odor and thelike of dogs and cats. The deodorization spray comprises, by mass, 5-8% of a Spanish bayonet extract, 4-5% of a green tea extract, 6-8% of an origanum oil extract, 4-5% of a persimmon extract, 4-5% ofa horseradish extract, 3-4% of zinc diricinoleate, 5-6% of an emulsifier, 1-2% of a stabilizing agent, 1-2% of a pH value regulator and the balance purified water. It is proved through deodorizationeffect identification that the deodorization performance of the spray is good, and the spray can quickly eliminate ammonia gas, hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfideand various common odor molecules of the pets within 5 minutes. Meanwhile, pathogenic microorganisms can be effectively inhibited and killed, and generation of odor can be inhibited from the source.