The invention relates to the technical field of environmental protection equipment, in particular to an aeration air flotation machine, which is used for carrying out aeration and stirring treatment on sewage, reducing the volume of bubbles, increasing the number of the bubbles and increasing the impurity adsorption capacity, and meanwhile, improving the impurity removal effect and improving the practicability and reliability through repeated aeration and adsorption effects. The aeration air flotation machine comprises a box body, a support, a water inlet pipe, a water inlet valve, a first mounting plate, a first motor, a first speed reducer, a first gear, a first mounting block, a first transmission shaft, a second gear, two groups of third gears and two groups of second transmission shafts; a first cavity is formed in the box body, the top end of the first cavity is communicated with a through opening, the bottom end of the box body is connected with the top end of the support, a partition plate is arranged on the lower side of the support, and the side input end of the water inlet pipe is communicated with the lower side of the left end of the first cavity.