With the continuous development of the city and the increase of the population, the construction of high-rise buildings, shopping malls, schools, subway stations, airports, stadiums, exhibition halls, hospitals and other population-intensive public places is also increasing. However, there are concerns about the safety of these sites. In order to protect the life and property safety of the public, B1 level halogen-free low-smoke flame-retardant cable came into being and has become an essential f