The invention relates to a desulfurization waste liquid treatment and reuse system. The desulfurization waste liquid treatment and reuse system includes a desulfurizing tower, a filter pressing device, a reduction tower, a desulfurization waste liquid distributing device, an aeration device, a heating device, a flocculant charging device, a sedimentation basin, a desulfurization waste liquid waterpump and a reduction liquid water pump, wherein the desulfurizing tower is provided with a flue gas inlet, a desulfurizing agent inlet, a desulfurization waste liquid outlet and an exhaust port, a tower body of the reduction tower is provided with a flocculant inlet, the desulfurization waste liquid distributing device is arranged in the tower body, the aeration device is provided with an aeration nozzle group located on the lower side of the desulfurization waste liquid distributing device, the sedimentation basin is provided with a reduction liquid cleaning water pump, an inlet of the desulfurization waste liquid water pump communicates with the desulfurization waste liquid outlet, and an inlet of the reduction liquid water pump communicates with an inner cavity of the reduction tower;and a waste residue outlet of the sedimentation basin communicates with the filter pressing device, an outlet of the desulfurization waste liquid water pump communicates with the desulfurization wasteliquid distributing device, an outlet of the reduction liquid water pump communicates with a reduction liquid inlet of the sedimentation basin, and an outlet of the reduction liquid cleaning water pump communicates with the desulfurizing agent inlet. According to the desulfurization waste liquid treatment and reuse system, treatment and reuse of desulfurization waste liquid are convenient, the amount of a desulfurizing agent is small, and the desulfurization effect is good.