The invention relates to a method for realizing opening of a blast furnace or fast ignition during intermediate overhaul, and belongs to the technical field of iron-making through the blast furnace. Before the opening of the furnace or air supply during the intermediate overhaul, an oxygen tube 1 is pre-buried in an iron notch, an oxygen flowmeter and a pressure gauge are mounted on the oxygen tube, a passivated magnesium particle conveying device is simultaneously mounted on the oxygen tube 1 and is connected with the oxygen tube through a tee. An upper valve of a material tank is used for adding magnesium particles and a lower valve of the material tank is used for controlling the blanking speed. When in the opening of the blast furnace or the air supply during the intermediate overhaul, a hot air pipeline needs to be used for blowing particulate magnesium into a furnace hearth together with oxygen, during the process of blowing the oxygen at the iron notch, and two material tanks of the passivated magnesium particle conveying device are used for blanking by turns, thereby keeping the magnesium spraying process continuous and fow. The method has the advantages of realizing the fast ignition of the furnace hearth of the blast furnace, ensuring timely iron tapping from the iron notch and preventing early slag from being excessive sticky.