The invention discloses a casting waste gas processing system with a four-tower-combination plasma body. The casting waste gas processing system with the four-tower-combination plasma body comprises a gas skirt, a first spray tower, a second spray tower, a plasma body processor and a third spray tower which are arranged above an exhaust-pipe outlet. The casting waste gas processing system with the four-tower-combination plasma body has the advantages that the industrial operation is convenient, clean production is achieved, after the casting waste gas is processed with the four-tower-combination plasma body, not only can the flue-gas temperature of the casting waste gas be lowered, but also the particulate matter and nitric oxide in the casting waste gas are removed effectively, and the problem that the casting waste gas pollutes the environment is solved completely.