The invention relates to a preparation method of a catalyst for decomposing ozone in high-humidity tail gas, and the method comprises the following steps: loading an active component on ZSM-5 molecular sieve powder, and preparing molecular sieve-silicon dioxide for catalytic decomposition of the ozone in the high-humidity tail gas aerogel by using the ZSM-5 molecular sieve powder. Compared with the prior art, the molecular sieve-silicon oxide composite aerogel prepared in the invention has a hydrophobic surface, can prevent condensation of water vapor on the surface of the catalyst, effectively improves the high humidity resistance of the catalyst, has a highly developed pore structure, has small resistance to tail gas, and saves power energy consumption.