A flue gas condensation water extraction system, comprising: a flue gas condensation end system; a flue gas refrigeration source end system; and a water supply and drainage system, wherein the flue gas condensation end system comprises a desulfurization absorption tower, a flue gas purification condensation tower, wherein the desulfurization absorption tower is provided with a flue gas inlet, wherein the flue gas purification condensation tower is disposed above the desulfurization absorption tower, wherein the flue gas purification condensation tower is provided with a flue gas outlet, a water inlet, and a drainage port, wherein the flue gas refrigeration source end system comprises a cooling tower, wherein the water inlet is connected to the cooling tower via a circulating water supply pipe, wherein a circulating water pump is arranged on the circulating water supply pipe, characterized in that, the flue gas condensation end system comprises a condensate storage tank, wherein the drainage port is connected to the condensate storage tank via a descending condensate water pipe, wherein the cooling tower is connected to the condensate storage tank via a circulating water return pipe, wherein the circulating water return pipe and the circulating water supply pipe are respectively provided with valves, wherein the water supply and drainage system includes an underground water storage tank, which is connected to the condensate storage tank via a water filling pipe, wherein the water filling pipe is provided with a water pump, wherein said underground water storage tank is connected to the circulating water return pipe and circulating water supply pipe via the drain pipe, and wherein the drain pipe is provided with a drain valve. a flue gas condensation end system; a flue gas refrigeration source end system; and a water supply and drainage system, wherein the flue gas condensation end system comprises a desulfurization absorption tower, a flue gas purification condensation tower, wherein the desulfurization absorption tower is provided with a flue gas inlet, wherein the flue gas purification condensation tower is disposed above the desulfurization absorption tower, wherein the flue gas purification condensation tower is provided with a flue gas outlet, a water inlet, and a drainage port, wherein the flue gas refrigeration source end system comprises a cooling tower, wherein the water inlet is connected to the cooling tower via a circulating water supply pipe, wherein a circulating water pump is arranged on the circulating water supply pipe, characterized in that, the flue gas condensation end system comprises a condensate storage tank, wherein the drainage port is connected to the condensate storage tank via a descending condensate water pipe, wherein the cooling tower is connected to the condensate storage tank via a circulating water return pipe, wherein the circulating water return pipe and the circulating water supply pipe are respectively provided with valves, wherein the water supply and drainage system includes an underground water storage tank, which is connected to the condensate storage tank via a water filling pipe, wherein the water filling pipe is provided with a water pump, wherein said underground water storage tank is connected to the circulating water return pipe and circulating water supply pipe via the drain pipe, and wherein the drain pipe is provided with a drain valve. wherein the flue gas condensation end system comprises a desulfurization absorption tower, a flue gas purification condensation tower, wherein the desulfurization absorption tower is provided with a flue gas inlet, wherein the flue gas purification condensation tower is disposed above the desulfurization absorption tower, wherein the flue gas purification condensation tower is provided with a flue gas outlet, a water inlet, and a drainage port, wherein the flue gas refrigeration source end system comprises a cooling tower, wherein the water inlet is connected to the cooling tower via a circulating water supply pipe, wherein a circulating water pump is arranged on the circulating water supply pipe, characterized in that, the flue gas condensation end system comprises a condensate storage tank, wherein the drainage port is connected to the condensate storage tank via a descending condensate water pipe, wherein the cooling tower is connected to the condensate storage tank via a circulating water return pipe, wherein the circulating water return pipe and the circulating water supply pipe are respectively provided with valves, wherein the water supply and drainage system includes an underground water storage tank, which is connected to the condensate storage tank via a water filling pipe, wherein the water filling pipe is provided with a water pump, wherein said underground water storage tank is connected to the circulating water return pipe and circulating water supply pipe via the drain pipe, and wherein the drain pipe is provided with a drain valve.