The invention relates to a preparation method of a denitration catalyst based on a mesoporous titanium dioxide carrier. The preparation method comprises the following steps of: adding cetyl trimethyl ammonium bromide into isopropanol and magnetically stirring the mixture in a membrane sealed container to generate a solution A; mixing cerous nitrate, antimony acetate, tantalum pentachloride, tetrabutyl titanate, isopropanol and hydrochloric acid to generate slurry B; and adding the slurry B into the solution A to stir and putting the mixture in a water bath pot to heat and calcine to prepare the denitration catalyst. The catalyst prepared by the method is wide in denitration temperature and the denitration rate is up to 90%.