Throat armor is very important for blast furnace in metallurgical industry, and its quality determines whether the procedure of blast furnace smelting can be carried out steadily for a long time. In this paper, the methods of mathematical simulation and actual production of blast furnace are applied, and the damage mechanism for throat armor is analyzed and studied. The results show that, the high temperature erosion and heat stress are the main reasons for throat armor damage, which make it upwarp falling, deform and fall off. According to the research of practical usage of throat armor, it proves that the result of mathematical simulation is reasonable. So the design parameters should be adjusted and optimized in processes of throat armor casting, and it is also reasonable and necessary to use the water-cooling throat armor.