The dissolved air flotation sewage treatment machine is a steel structure, and its working principle is that air is pumped into a pressure dissolved gas tank and forcibly dissolved in water at a pressure of 0.5 MPa. In the case of sudden release, the air dissolved in the water is released, forming a large number of dense microbubbles that adsorb suspended solids during the slow rise process, causing the density of suspended solids to decrease and rise, achieving the goal of removing SS and CODcr. This product is suitable for wastewater treatment in industries such as petroleum, chemical, papermaking, leather, printing and dyeing, food, starch, etc.