The invention discloses a desulfuration absorption system capable of deeply purifying flue gas and used for a boiler. The system comprises a tower body, wherein the tower body comprises a slurry supply part, a gas inlet part and an electric precipitation part from the bottom up; the electric precipitation part comprises a box body fixed on the tower body, a plurality of anode pipes distributed in the box body, and corona electrodes arranged in the anode pipes in a penetrating manner; the upper ends of the anode pipes are open, and the lower ends of the anode pipes are in seal shapes; gas inlet cavities allowing lower flue gas to enter can be formed among side walls of the circumferentially distributed anode pipes; the upper ends of the gas inlet cavities are in seal shapes; and breathing holes communicated with the gas inlet cavities and the anode pipes are distributed in the side walls of the anode pipes. The system has the following advantages and effects that flue gas flow channels in the electric precipitation part are changed and a flow rate is reduced, so that a purification effect of the electric precipitation part is improved, and exhausted flue gas has higher cleanliness.