Efficient multi-stage indoor air purifier

An efficient multi-stage indoor air purifier comprises a middle shell, the middle shell is of a rectangular frame structure, the two sides of the middle shell are each of an opening structure, a multi-stage filtering assembly is embedded in the front portion of the interior of the middle shell, and the multi-stage filtering assembly comprises a cover plate, a gauze plate, an efficient filtering plate and an activated carbon filtering plate; an air gathering plate is assembled and connected to the tail part of the middle shell, a rear cover body is assembled and connected to the back surface of the air gathering plate, a fan is mounted at the center of the rear cover body, and air outlets are formed in the two sides of the rear cover body; according to the air purifier, four-stage filtration can be carried out on air, and most impurities, particles and harmful gas in the air are eliminated; the ultraviolet rays with proper wavelength can destroy DNA or RNA in microbial organism cells; the high-voltage plasma g