The invention discloses a mixing and spraying device. The mixing and spraying device comprises a material box, a gas and water mixing device, a water inlet pipe and a gas inlet pipe, wherein the material box is used for storing water and ozone; the gas and water mixing device is used for mixing the ozone and the water; the water inlet pipe is used for conveying the water in the material box to a water inlet of the gas and water mixing device; the air inlet pipe is used for conveying the ozone in the material box to an air inlet of the gas and water mixing device. The mixing and spraying device has the advantages that the ozone and the water can be fully mixed, the dissolving rate of the ozone is greatly improved, and the waste of the ozone is avoided.