A CO2 recovery system comprising: a CO2 recovery unit comprising: a CO2 absorber that absorbs and reduces CO2 in flue gas containing CO2 using a CO2 absorbent by bringing the flue gas into contact with the CO2 absorbent; and an absorbent regenerator that regenerates a CO2 absorbent having absorbed CO2 in the CO2 absorber to obtain a CO2 absorbent; a CO2 compression unit comprising: a plurality of compressors (61-1, 61-n) that compress CO2 gas emitted from the absorbent regenerator; and a plurality of separators (63-1, 63-n) being respectively located between any two of the plurality of compressors (61-1, 61-n) to separate moisture contained in the CO2 gas as condensed water from the CO2 gas by cooling compressed CO2 gas; and a first condensed water supply line (65A-65D) that supplies the condensed water separated from the CO2 gas through any one of the plurality of separators (63-1, 63-n) into a system in which the CO2 absorbent circulates between the CO2 absorber and the absorbent regenerator, wherein the condensed water separated from any one of the plurality of separators (63-1, 63-n) is supplied to inside of the CO 2 absorber, to the CO 2 absorbent circulating between the CO 2 absorber and the absorbent regenerator, to return water to be supplied to the absorbent regenerator from a separation drum that separates water from the CO 2 gas emitted from the absorbent regenerator, and to a top circulating-water line of the absorber. a CO2 recovery unit comprising: a CO2 absorber that absorbs and reduces CO2 in flue gas containing CO2 using a CO2 absorbent by bringing the flue gas into contact with the CO2 absorbent; and an absorbent regenerator that regenerates a CO2 absorbent having absorbed CO2 in the CO2 absorber to obtain a CO2 absorbent; a CO2 absorber that absorbs and reduces CO2 in flue gas containing CO2 using a CO2 absorbent by bringing the flue gas into contact with the CO2 absorbent; and an absorbent regenerator that regenerates a CO2 absorbent having absorbed CO2 in the CO2 absorber to obtain a CO2 absorbent; a CO2 compression unit comprising: a plurality of compressors (61-1, 61-n) that compress CO2 gas emitted from the absorbent regenerator; and a plurality of separators (63-1, 63-n) being respectively located between any two of the plurality of compressors (61-1, 61-n) to separate moisture contained in the CO2 gas as condensed water from the CO2 gas by cooling compressed CO2 gas; and a first condensed water supply line (65A-65D) that supplies the condensed water separated from the CO2 gas through any one of the plurality of separators (63-1, 63-n) into a system in which the CO2 absorbent circulates between the CO2 absorber and the absorbent regenerator, a plurality of compressors (61-1, 61-n) that compress CO2 gas emitted from the absorbent regenerator; and a plurality of separators (63-1, 63-n) being respectively located between any two of the plurality of compressors (61-1, 61-n) to separate moisture contained in the CO2 gas as condensed water from the CO2 gas by cooling compressed CO2 gas; and a first condensed water supply line (65A-65D) that supplies the condensed water separated from the CO2 gas through any one of the plurality of separators (63-1, 63-n) into a system in which the CO2 absorbent circulates between the CO2 absorber and the absorbent regenerator, wherein the condensed water separated from any one of the plurality of separators (63-1, 63-n) is supplied to inside of the CO 2 absorber, to the CO 2 absorbent circulating between the CO 2 absorber and the absorbent regenerator, to return water to be supplied to the absorbent regenerator from a separation drum that separates water from the CO 2 gas emitted from the absorbent regenerator, and to a top circulating-water line of the absorber.