The invention relates to a quick-acting furnace repairing method of a converter. The quick-acting furnace repairing method comprises the following steps: determining a furnace repairing position; increasing the final temperature of the prior converter before furnace repairing; increasing the content of MgO in converter final slags; performing deslagging; pouring furnace repairing materials; sintering the furnace materials; reinforcing the sintered furnace materials; after furnace repairing is performed for 40 minutes, enabling about two tons of molten iron to be slowly poured into the converter; gathering the molten iron to a furnace repairing material region through a shaking furnace; performing resintering on the furnace repairing materials for 5-10 minutes through high temperature molten iron; and after furnace repairing is completed, starting to prepare the smelting of the next converter. According to the quick-acting furnace repairing method disclosed by the invention, on one side, by a method of performing heat preservation with coal gas and adding oxygen for combustion-supporting, the sintering temperature of the furnace repairing materials is increased; and on the other side, in the later stage of furnace repairing, through the high-temperature molten iron, high melting point phase of the furnace repairing materials is sintered once again, so that the sintering effect of the furnace repairing materials is guaranteed. Compared with the furnace repairing time through a conventional furnace repairing technology, the furnace repairing time of the quick-acting furnace repairing method disclosed by the invention is shortened by 10-15 minutes; and after the technology is adopted, the durable converter number of the furnace repairing materials is prolonged by 3-5 times.