The invention relates to a stemming at a taphole; the weight percentages of the components are the following: 20 to 40 of corundum, 10 to 20 of silicon carbide, 3 to 10 of silicon nitride, 10 to 23 of coke powders, 1 to 5 of graphite powders, 3 to 10 of sericite, 1 to 5 of active alumina micropowders, 5 to 15 of clay, 5 to 10 of pyrophyllite, 1 to 3 of metal powders, and +15 to 25 of water-free binder. The stemming adds a plurality of materials with plasticity and good cohesiveness to cause the stemming to easily block the hole and fill interspaces, with good binding performance of new stemming and old stemming; materials with medium and high temperature expansion are added to reduce the size of the stemming contraction at high temperature, and cracks can be avoided; materials with sintering function within different temperature areas are added, so the stemming has good sintering strength in different temperature scopes; materials with high-temperature resistance and good erosion resistance are added, and thus the stemming has high strength at high temperature, washing resistance and erosion resistance.