The invention discloses a novel air conditioner purifier which comprises a front shell and a back panel, wherein an upper filter screen seat is arranged between the front shell and back panel; the inner wall of the front shell is provided with a plurality of second grooves; a plurality of first filter screen cavities are arranged in the upper filter screen seat; the back panel is provided with a plurality of first slide rails; the bottom shell of the upper filter screen seat is provided with a plurality of first grooves; the first slide rails are matched and connected with the first grooves; the bottom of the upper filter screen seat is provided with a first filter screen seat and a second filter screen seat; the first filter screen seat is connected with a first back shell in a sliding mode; the second filter screen seat is connected with a second back shell in a sliding mode; and a second filter screen cavity is respectively arranged in the first filter screen seat and second filter screen seat. The novel air conditioner purifier can adjust according to different air conditioner sizes when in use, and thus, is convenient to use and wide in applicability. The novel air conditioner purifier is installed on the air return port of the air conditioner without providing any independent ventilation system, and thus, is energy-saving and environment-friendly. By adopting the double filter screens, the air conditioner purifier has favorable filtering effect, and the filter screens are convenient for demounting and cleaning.