Device for treating waste gas

The invention relates to a device for treating waste gas, which comprises a spraying-cleaning device. The spraying-cleaning device comprises a tower body and a spraying device, wherein a containing cavity, a helical structure and a packing layer are successively arranged from the bottom to the top of the inside tower body, and the containing cavity is parted into a first cavity, a second cavity and a third cavity. The bottom of the tower body is provided with an air inlet and a water outlet, both are connected with the first cavity; the top of the tower body is provided with an air outlet connected with the third cavity. A spraying device comprises a first spraying unit and a second spraying unit; a gas cleaning unit comprises a cleaning cavity body which is provided with an air inlet and an air outlet, wherein the air inlet is connected with the air outlet, the cleaning cavity comprises a plasma reaction chamber which is provided with a plasma electric generator. After multistage purification, the device for