The invention discloses an air filtering device capable of intelligently adjusting the hole diameters of filter screens. The air filtering device comprises a box body and a control chamber. The control chamber comprises a processor, a driving device and a navigation device; the navigation device is used for setting the travelling route of the filtering device, and the box body comprises an air pumping device, sealed connectors, a glass delivery tube and a negative-ion generator; a plurality of through holes are formed in the front portion of the box body, and the sealed connectors are arrangedin the through holes; the air pumping device is located on the front portion of the box body and used for pumping outside air into the box body, and the glass delivery tube is connected with the sealed connectors; a plurality of grooves are formed in the radial direction of the glass delivery tube and used for storing the first filter screen and the second filter screen, and pop-up devices are arranged on the side faces of the grooves and used for popping out the filter screens in the grooves; the glass delivery tube further comprises an air pressure sensor which is located on the zone between the air pumping device and the filter screens and used for detecting the air pressure inside the glass delivery tube, and the negative-ion generator is located at the tail of the box body and connected with the driving device; and through holes surrounding the negative-ion generator are formed in the tail of the box body.