Disclosed are an apparatus and method for preparing a manganese oxide-titania catalyst. The apparatus for preparing a manganese oxide-titania catalyst includes: a vaporizer vaporizing a manganese precursor and a titanium precursor; a carrier gas supply line supplying a carrier gas, which carries precursor vapors vaporized by the vaporizer to a reactor, to the vaporizer; an oxygen supply line supplying an oxygen source to the reactor; the reactor reacting the precursor vapors with the oxygen source to synthesize a manganese oxide-titania catalyst; and a collector condensing and collecting the manganese oxide-titania catalyst synthesized in the reactor. And, the method for preparing a manganese oxide-titania catalyst includes: 1) vaporizing a manganese precursor and a titanium precursor; 2) carrying precursor vapors (vapors of the manganese precursor and the titanium precursor) and an oxygen source to a reactor; 3) reacting the precursor vapors and the oxygen source to synthesize a manganese oxide-titania catalyst; and 4) condensing and collecting the manganese oxide-titania catalyst. According to the present disclosure, mass production of manganese oxide-titania catalysts with high decomposition efficiency of organic compounds can be prepared through fewer and continuous processes.