The invention relates to a flue gas desulfurization technology for a uniform flow field internal reflux circulating fluidized bed. Core equipment, namely a reactor, of the flue gas desulfurization technology comprises a direct-current streamline bottom air inlet, a guide plate, a central built-in absorbent distributor, a flue gas accelerator, a humidified activated nozzle, a rotating-stream tray gas-solid separator and a central outlet flue on the upper part of a cylinder body of the reactor form the bottom up in turn, wherein the inside of an inlet flue of the reactor is provided with a dual-chip circular uniform flue gas distribution guide plate; and the inside of the reactor is provided with the central built-in absorbent distributor, the 'Laval nozzle' - type flue gas accelerator, thetwo-stage double-fluid humidified activated nozzle and the rotating-stream tray gas-solid separator. The flue gas desulfurization technology is reasonable in configuration; flue gas in the reactor obtains ideal and stable uniform fluid field and temperature field; an absorbent obtains high circulation ratio and high utilization rate; and two-stage humidification can effectively improve the reaction activity of the absorbent, and can also effectively avoid wetted wall, fouling and collapsed bed. Moreover, the flue gas desulfurization technology guarantees the desulfurization efficiency, obviously reduces the dust content of the outlet flue, greatly lightens the load of a rear bag-type duster, and solves the technical problems in a flue gas desulfurization technology for a semi-dry circulating fluidized bed.