The invention discloses a repairing method of an ultra-low-carbon application material tundish. The repairing method comprises an application process, a maintenance process and a baking process. The application process comprises the steps of firstly, applying an application material to the tundish wall to form a thin paste layer, wherein the amount of the application material accounts for 20-30% of the amount of added water; and after the thin paste layer is completely dry, applying the application material to form a thick paste layer in a spattering manner, wherein the amount the applicationmaterial accounts for 14-17% of the amount of the added water. The maintenance process comprises the steps of firstly, conducting air-drying for 1-2 hours after application; and then, putting a red ladle cover obtained from a hot ladle in a covering manner, and conducting maintenance for one hour or longer. The baking process comprises the steps of firstly, conducting low-flame baking at the temperature of 300-600 DEG C; then, conducting moderate-flame baking at the temperature of 600-800 DEG C; and finally, conducting high-flame baking at the temperature of 800-1100 DEG C. By means of the method, repairing quality of the carbon-free application material tundish is improved; the strength of the application material is improved through maintenance control; the using effect of the tundish isimproved through control over the baking temperature; the production effect of an IF steel is guaranteed; and after being used, the tundish is convenient to disassemble. In the continuous casting useprocess, the tundish obtained through the method has the beneficial effects of being high in strength, free of collapse and convenient and fast to construct; and after being used, the tundish is convenient to disassemble.