Method for waste gas dedusting and dedusting agent

A method and device for waste gas dedusting and a dedusting agent used in the method. A dust-containing waste gas and an organic dedusting agent are introduced into a dedusting tower, respectively, and make contact with each other in the tower; at least part of the water vapor in the dust-containing waste gas is condensed, and the organic dedusting agent and the condensed water adsorb solid particles, acidic pollutants, organic pollutants and/or heavy metal compounds in the dust-containing waste gas; and the resulting purified gas is emptied out or subjected to a subsequent process. The organic dedusting agent comprises a non-toxic and high boiling point organic solvent composition, being two or more selected from cooking oil, silicone oil, modified silicone oil, liquid-state asphalt oil, tung tree seed oil, liquid-state paraffin wax oil, mineral oil, palm oil and waste cooking oil.