The dissolved air flotation machine is an efficient and stable water treatment equipment that clarifies wastewater by removing oils, greases or other solid suspended matter. Its process design is to dissolve gas into water to the maximum extent under pressure, striving to be in a supersaturated state, and then release air at atmospheric pressure in the flotation tank. The released air forms a large number of tiny bubbles, which adhere to the suspended matter in the water, causing it to float to the water surface with the bubbles, forming scum, which is then removed by a scraping device.