The utility model relates to a sulfur recovery flue gas purification treatment technical field discloses a flue gas desulfurization tower, flue gas desulfurization tower is including inside tower body(10) that have cavity (11) of injecing, be provided with the edge in cavity (11) a plurality of spray group (20) of the direction of height interval arrangement of cavity (11), every spray group (20)including can make progress or downwards one -way spray one -way spray layer (21) and can make progress and the two -way two -way layer (22) that sprays that sprays downwards, one -way spray the layer (21) and follow on the two -way layer (22) that sprays the direction of height interval of cavity (11) sets up. The utility model discloses an adopt the one -way layer that sprays to spray simultaneously with the two -way layer that sprays, the cross section that makes flue gas desulfurization tower by the thick liquid totally, even earth shifter lid, can not only improve and spray abstergent intensity, can realize the efficient desulfurization degree under the prerequisite of guaranteeing less flue gas pressure drop and thick liquid spraying amount in addition, can also reduce slurry circulating pump's electric consumption simultaneously.