The invention relates to a dustproof flotage-proof net for an air conditioner. The dustproof flotage-proof net comprises a net releasing drum, a sealing drum, net walking slots and a net collecting drum; the net walking slots are symmetrically arranged on and under an outdoor unit fan of the air conditioner; the net releasing drum and the net collecting drum shaft are symmetrically arranged at the left and right sides of the outdoor unit fan of the air conditioner; a net releasing shaft is arranged in the net releasing drum; a net collecting shaft is arranged in the net collecting drum; one end of the sealing net is fixed on the net releasing shaft and is wound layer by layer and the other end of the sealing net extends from the slot port of the net releasing drum to be connected with the net collecting shaft; the bottom end of the net collecting shaft is connected with a rocker handle; upper and lower ends of the sealing net are respectively led into the net walking slots; the net releasing drum, the net walking slots and the sealing net form an air filtering device. The dust and flotage can be isolated outside the outdoor unit of the air conditioner and are prevented from entering a radiator of the air conditioner. After the dustproof flotage-proof net is used for a certain time, for the dust and flotage on the filter net, an idler wheel at the right side is shaken, and a new filter net is rotated to an air inlet to achieve the dedusting and flotage removing actions.