The invention discloses a renewable wet flue gas desulfurization technology to solve a problem of oversize water vapor consumption during the regeneration of a rich solution in a regeneration tower of present renewable wet flue gas desulfurization technologies. The technology comprises the following steps: carrying out cooling adsorption of the flue gas, wherein the absorbent used in the invention is an inorganic absorbent; and regenerating the rich solution. The rich solution regeneration is carried out in the regeneration tower (12), the top pressure of the regeneration tower (12) is lower than 1atm, and the regeneration is carried out under a reduced pressure condition. The reboiling system of the regeneration tower (12) is provided with a hot water or water vapor reboiler (14), and the reboiling heat source medium is the hot water or the water vapor. The technology can be used in petroleum refining enterprises, electricity generation enterprises, smelting enterprises and the like, and can realize the desulfurization treatment of the flue gas.