Waste gas collecting and discharging device for building construction

The utility model relates to the technical field of waste gas treatment, in particular to a waste gas collecting and discharging device for building construction, which comprises a purifying box, the purifying box is fixedly welded at the top of a circulating water tank, a pump body is fixedly mounted at the top end of the circulating water tank, and two ends of the pump body are connected with water pipes. The pump body can pump water in the circulating water tank into the spraying pipe, the water in the spraying pipe can be sprayed out through the multiple spraying heads, the water is sprayed into the filler layer to form water drops, the water drops drip down along gaps of the filler, and waste gas can be fused with the water drops of the mixed filler in the process of being discharged from bottom to top, so that the waste gas is treated; the treated waste gas can be purified by a plurality of activated carbon purification plates in the ascending and discharging process; and after the waste gas is discharg