The utility model discloses a system for SO2 in recovery tail gas, it includes first order circulation recovery system and second level circulation recovery system, and first order circulation recovery system includes scrubber, first recovery pump, transports a section of thick bamboo and first circulating slot, and the upper portion of scrubber is provided with the direction scrubber air inlet down of giving vent to anger, and the lower part of scrubber is provided with the scrubber discharge gate, and inside being provided with of scrubber sprays direction first shower head up, second level circulation recovery system includes reaction tower, second recovery pump and second circulating slot, and the top of reaction tower sets up the reaction tower gas outlet, and the bottom of reaction tower is provided with the reaction tower liquid outlet, and the well lower part of reaction tower is provided with the reaction tower air inlet, and inside being provided with of reaction tower sprays direction second shower head down. The utility model discloses the advantage lies in realizing that SO2's multistage circulation is retrieved in the tail gas, and resource utilization rate is high, and recovery efficiency is high, has reduced environmental pollution.