Flue gas comprehensive treatment method and device

The invention discloses a flue gas comprehensive treatment method and device. According to the method, flue gas is treated, enters into an absorption tower from the lower part of the absorption tower,and ascends inside the absorption tower, and is finally discharged after being subjected by cooling, SO2 removal, dedusting and demisting, phase change and condensation,and deep removal of pollutantsand heating and reheating. The flue gas comprehensive treatment device adopting the method includes the absorption tower, wherein an oxidization unit, a chilling condensation cooling unit, an SO2 absorption tower, a dedusting and demisting unit, a phase change and condensation and pollutant deep removal unit, an efficient demisting unit and a heating and reheating unit are sequentially arranged inside the absorption tower from bottom to top; a flue gas inlet is arranged between the oxidization unit and the chilling condensation cooling unit; a flue gas outlet is arranged at the top of the heating and reheating unit. A