The utility provides a near-zero discharging absorption tower for sulfur dioxide in a coal-fired power plant. The near-zero discharging absorption tower comprises a spray tower body, wherein a slurry pond is arranged at the lower part in the spray tower body, an absorption region is arranged above the slurry pond, a first partition board and a second partition board are arranged in the spray tower body, the absorption region is separated into a first spraying chamber, a flue gas steering chamber and a second spraying chamber by the first partition board and the second partition board, the first partition board stretches into the slurry pond from the upper part in the spray tower body, and the second partition board stretches to the top of the spray tower body from the upper part of the slurry pond; a flue gas inlet communicated with the first spraying chamber is formed in one side of the spray tower body, and a flue gas outlet communicated with the second spraying chamber is formed in the other side of the spray tower body; spraying layers are arranged in the first spraying chamber and the second spraying chamber. The near-zero discharging absorption tower is different from a structural form of an existing spray tower and has the advantages of low construction investment and operation cost and high desulphurization efficiency.