The utility model discloses an exhaust gas desulfurization absorption tower, which comprises a tower body. An exhaust gas outlet is arranged at the top part of the tower body; a slurry pool used for containing a desulphurization washing liquid is arranged at the bottom part of an inner cavity of the tower body; a washing liquid spray pipe transversely arranged inside the tower body is positioned below the exhaust gas outlet and communicated with the slurry pool through a recirculating pump; an exhaust gas inlet is arranged in the middle of the tower body and is positioned below the washing liquid spray pipe; following the downward vertical direction, at least part of the tower body adopts a structure of an outer expansion bell mouth with gradually increased ring diameters; and the exhaustgas inlet is arranged on the structure of the outer expansion bell mouth. The outer expansion bell mouth structural design adopted by the tower body eliminates the inlet inclination angle of the absorption tower, and changes an inclined exhaust gas inlet pipeline into a horizontal pipeline, thereby reducing the design difficulty, saving the material requirement of an engineering project, reducingthe pressure loss of an inlet section, and achieving the purposes of optimizing design methods and reducing the construction work cost and the operation energy consumption of the absorption tower.