The invention relates to an integrated treatment device and an integrated treatment method of organic waste gas. The integrated treatment device comprises a washing and air-floatation recovery unit and a bioreactor, wherein the washing and air-floatation recovery unit comprises a washing tower, an air flotation tower and a cooler, and the washing tower is connected with the air flotation tower by a liquid communicating pipe at the bottom; the cooler is arranged between the washing tower and the air-flotation tower and forms a closed loop in common by virtue of a circulating pump; the tops of the washing tower and the air-flotation tower are respectively provided with an exhausting port; the exhausting ports are gathered by virtue of a pipeline and then are connected to the bioreactor. The integrated treatment device has the advantages that the structure is simple, the treatability is strong, partial organic matters can be recovered and utilized, and comprehensive and effective treatment of the organic waste gas can be realized.