Flue gas desulfurization system

The utility model relates to a flue gas desulfurization system which comprises a desulfurization flue for flue gas to enter, an outlet of the desulfurization flue is connected with an exhaust fan so as to form a negative pressure environment in the desulfurization flue, and the side part of the desulfurization flue is provided with a desulfurizing agent adding port for a desulfurizing agent to enter; the flue gas desulfurization system comprises a weightlessness scale used for weighing a desulfurizing agent, the weightlessness scale comprises a support and a weighing bin, and the weighing bin is supported on the support through a weighing sensor; a weighing bin exhaust port is formed in the weighing bin; the flue gas desulfurization system further comprises a weighing bin exhaust pipe, one end of the weighing bin exhaust pipe is connected to the weighing bin exhaust port through a hose, and the other end of the weighing bin exhaust pipe is connected to the desulfurization flue, so that the desulfurization flu