The utility model relates to a sulfuric exhaust gas emptying control device, relating to a device for preventing leakage of an emptying pipeline valve to produce excessive sulfuric exhaust gas. The sulfuric exhaust gas emptying control device is characterized by comprising an emptying pipeline valve, a negative pressure chamber tube, an exhaust gas chimney valve, wherein a butterfly valve is adopted as the emptying pipeline valve and is in flange connection with an emptying pipeline; the negative pressure chamber tube is a sectioned tube in flange connection with the emptying pipeline valve, and the sectioned tube is provided with a pumping tube; and a butterfly valve is adopted as the exhaust gas chimney valve, one end of the butterfly valve is coupled with the negative pressure chamber tube, and the other end of the butterfly valve is in flange connection with an exhaust gas chimney. When an emptying valve is not closed tightly or is subjected to leakage, leaking flue gas enters the negative pressure chamber tube between the emptying pipeline valve and the exhaust gas chimney valve at first, and part of leaking flue gas is guided into a system by a vacuum pumping device for treatment. The sulfuric exhaust gas emptying control device has the advantages of simple design and operation, reliable operation and small maintenance workload.