The utility model discloses a DC combination tower sulfur dioxide treatment system, including heterogeneous desulfurizing tower of DS and CST turbogrid tray tower, DS passes through pipeline and boiler connected in heterogeneous desulfurizing tower top, the heterogeneous desulfurizing tower lower extreme of DS is established on the sedimentation tank, and rather than the intercommunication, CST turbogrid tray tower lower extreme is established on the sedimentation tank, and rather than the intercommunication, CST turbogrid tray top of the tower end passes through pipeline intercommunication chimney through pipe connection draught fan, draught fan, the sedimentation tank lower part is equipped with sewage port, the heterogeneous desulfurizing tower upper portion of DS is inserted through the circulating pump in the sedimentation tank middle part, through the circulating wind pipe intercommunication on the pipeline between the heterogeneous desulfurizing tower of draught fan and chimney and boiler and DS. The utility model provides a DC combination tower has been solved the wet flue gas desulfurization flue gas and has been carried " secondary pollution " problem that the emission of aerosol particles thing leads to, the system has reduced the area when each single tower series uses, saving investment expense, the reinforcing operational reliability of system.