The invention specifically relates to mesoporous titanium apatite, and a preparation method and application thereof, belonging to the technical field of removal of harmful gases produced during interior decoration. The mesoporous titanium apatite has a chemical formula of TiCa<5-x>(PO<4>)<3+2/3x>(F, Cl, OH), wherein x is no less than 1 and no more than 5. The mesoporous titanium apatite has a honeycomb porous structure, an average pore diameter of 10-25 nm, a specific surface area of 50-200 m<2>/g and a forbidden band width of 2.7 eV; and the mesoporous titanium apatite has powerful adsorption capability to harmful gases produced during interior decoration, is capable of oxidizing formaldehyde and the like into CO2 and H2O, and produces no secondary pollution.