At present, the proportion of cast bus duct in the bus industry is increasing, and many users pay more and more attention to the quality and safety of cast bus. In China, cast bus is mainly made of two materials, one is resin cast bus, the other is inorganic mineral volcanic rock full cast bus, Resin cast bus can be said to be a well-known cast bus type in the industry, but some problems have occurred in this bus in recent years, which has also attracted the attention of people in the industry. Compared with resin cast bus, cast bus duct has not been well known by many people. For those who have known this type of bus duct, In their hearts, they recognize this type of bus duct. It is a good choice for users, whether from the long-term development of the enterprise, use safety, energy conservation and environmental protection, or from the aspects of policy requirements, industry specifications, product characteristics, etc.