Steel continuous casting tundish is a steel structure intermediate container connecting liquid steel ladle and the mold system. Inside it is the castables, heat-insulating shield, nozzle brick, sizing nozzle and other refractory materials. The tundish is placed on the tundish car. It plays a role in reducing and balancing the ferrostatic pressure to smooth the liquid steel flow into the mold. This helps to reduce the compact and stirring on the liquid steel inside the mold caused by the pouring liquid steel. It also traps the impurities present in the steel liquid inside the tundish and brings them to float. This avoids the impurities from flowing into the mold to influence the quality of the billet.