Leakage detection method of blast furnace system

The invention discloses a leak detection method of a blast furnace system, which comprises leak detection in a blast furnace construction completion stage, and comprises the following steps: feeding a leak detection medium into a blast furnace through a vent header pipe; closing each blow-off valve; increasing the hot air pressure and the furnace top pressure to 0.15 MPa; performing low-pressure leakage test inspection on the blast furnace system by using an acoustic imager, marking a large leakage point, and releasing pressure and stopping leakage; the leakage detection medium is fed again, the pressure is increased to 0.05 MPa, rough detection is carried out, and large leakage points are marked and processed; increasing the pressure according to the gradient of increasing 0.1 MPa, repeatedly detecting the leakage, marking, releasing the pressure and stopping the leakage of each pressure level until the final leakage test pressure of 0.35 MPa is reached, performing detailed detection, making a record and exp