Purifying apparatus and purifying method for treating incineration flue gas

The invention discloses a purifying apparatus and purifying method for treating incineration flue gas. The purifying apparatus for treating incineration flue gas comprises a first fluidized bed, a second fluidized bed, a third fluidized bed and a dust remover, wherein the first fluidized bed, the second fluidized bed and the third fluidized bed are successively connected, the first fluidized bed is provided with an alkali lye inlet used for adding alkali lye into the first fluidized bed, the third fluidized bed is provided with an active carbon inlet used for adding active carbon into the third fluidized bed, a flue gas inlet of the dust remover is connected with a flue gas outlet of the third fluidized bed, and the inlet of the first fluidized bed is connected with an outlet of a flue gas quenching unit. The purifying apparatus for treating incineration flue gas in the invention has the advantages of good treatment effect, a wide treatment scope, stable treatment effect, etc.