This standard specifies the test method for evaluating the "non-combustibility" of homogeneous and non-homogeneous building materials under specific laboratory conditions. The core of the method involves placing the specimen in a tubular heating furnace maintained at a stable temperature of 750°C and continuously heating it. The combustion performance of the material is comprehensively determined by measuring and evaluating multiple key indicators, including the temperature rise inside the furnace, the temperature rise at the specimen's center and surface, the duration of sustained burning, and the mass loss. The standard provides detailed descriptions of the test apparatus (such as the heating furnace, thermocouple system, specimen holder, etc.), specimen preparation, conditioning procedures, and result interpretation. This method serves as one of the key criteria for determining the highest combustion performance classification (Class A) of building materials and is widely applied in fire safety assessments for various building products, such as walls and ceilings.