At present, the building exterior wall thermal insulation materials is one of the important projects inside decorate material sampling observation, this was related with its frequent fire accident. CCTV building fire, for example, is the result of using the flame retardant of organic heat preservation material. The material in the fire because of incomplete combustion and pyrolysis, will produce more smoke and toxic gases, and most people in the fire accident is inhaled smoke and toxic gases suffocated to death. So, building external wall thermal insulation material caused by fire risk is extremely high, easy to cause significant casualties accidents, the author work experience, talk about the cause of the fire and prevention countermeasures. A, the cause analysis of exterior wall thermal insulation materials, is the industry standard, product quality is uneven. At present, the link of the production and use of external thermal insulation material, a mess currently adopted in the construction field of organic heat preservation material mainly includes polystyrene board (EPS) and extruded plate (XPS) and polyurethane (PU) three, its biggest advantage is light weight, good thermal insulating, stays. The biggest defect is the difference in fire safety, easy to aging, easy to burn. Is widely used due to the low price of the two, the latter in the coefficient of thermal conductivity, construction performance and combustion performance and etc. Outer wall heat preservation material industry standard is not yet perfect, individual manufacturers in the loopholes in management, production of thermal insulation material is short of building fire protection design requirements, fire rating and fireproof limit also can not meet the national standards, product to market, for the building fire accident buried congenital safe hidden trouble. Second, long construction period, work safety hidden trouble. For the construction industry, energy-saving insulation is national policy, the wall heat preservation but also realize the important means of building energy efficiency, so the building insulation materials has a very wide range of applications. In reality, high-rise buildings, the construction of the large sports venues and other construction time limit for a project, generally for two to three years, cross each other all sorts of construction process, management of inconvenience. Individual managers ignore the screen control of fire hazard and fire control set of temporary water, put all his energy on pursuing the construction period and the compression cost.