The invention provides a high-carbon high-chromium high-niobium cast iron self-protection flux-cored wire. The flux-cored wire has a steel belt as an outer skin. The flux core comprises the following components in weight percentage: 10 to 30 percent of ferroniobium, 20 to 30 percent of high carbon ferrochrome, 0.1 to 3 percent of V, 0.2 to 3 percent of W, 0.6 to 0.8 percent of ferromanganese, 0.2 to 0.8 percent of 75 ferrosilicon, 20 to 30 percent of chromium carbide, 5 to 12 percent of graphite, 1 to 10 percent of aluminum-magnesium alloy, 1 to 5 percent of silicon carbide and 1 to 3 percent of ferroboron; and the percentage of a counter weight is between 46 and 54 percent. The high-carbon high-chromium high-niobium cast iron self-protection flux-cored wire has the advantages of high hardness, good wear resistance, good oxidation resistance and strong shock resistance, and is widely applied to grinding rolls and grinding disks of coal grinding machines in thermal power plants and cement plants, material charging equipment in blast furnaces(material charging slots, receiving cones, material storage areas and sieve plates), slag vertical mills, hammer heads and rollers of crushers and sintering equipment workpieces in steel plants.