Sulfur dioxide gas recovery system and method

The invention belongs to the technical field of environmental protection, and particularly relates to a sulfur dioxide gas recovery system and method. The system comprises a first-stage absorption tower, a second-stage absorption tower, a third-stage absorption tower and a fourth-stage absorption tower which are used for absorbing sulfur dioxide, and a first-stage buffer container, a second-stage buffer container, a third-stage buffer container and a fourth-stage buffer container which are used for storing absorption liquid, wherein the first-stage to fourth-stage absorption towers are sequentially connected along the trend of sulfur dioxide; the fourth to first-stage buffer containers are sequentially connected along the flowing direction of the absorption liquid; an absorption liquid outlet of each stage of absorption tower is directly connected with an inlet of the corresponding same-stage buffer container; the absorption liquid inlet of each stage of absorption tower is connected with the outlet of the co