The washing system mainly consists of washing tower, circulation pipeline, dosing pipeline, fog removal, etc. The exhaust gas enters the lower part of the scrubber through the pipeline, goes upstream, contacts with the absorption liquid from the top down, and absorbs the gas in the exhaust gas. The scrubber is provided with a fog removal layer, spray layer, filler layer and liquid storage tank from top to bottom, and the waste gas enters the scrubber from the air inlet below the tower, and passes through the filler layer and the fog removal layer from bottom to top. The spray water circulates from the liquid storage tank to the spray layer through the circulating pump, and the spray lye contacts and absorbs the tail gas from top to bottom, and falls back to the liquid storage tank at the bottom of the tower. Achieve reverse contact, absorption of exhaust gas function.