Heat shield of polysilicon CVD (chemical vapor deposition) reactor

The invention relates to the field of an energy-saving device for a polysilicon CVD (chemical vapor deposition) reactor. An integrated quartz heat shield with best performance in the prior art is difficult to enlarge in size, poor in pressure resistance capability and fragile; and the produced heat radiation is high. According to the technical scheme provided by the invention, the heat shield is formed by splicing two or more quartz glass components; the overall heat shield of the reactor is formed by sleeving and superposing one or more layers of the splicing parts, and is fixed on the inner wall of the reactor through a fixing part; and one layer of quartz glass closest to a silicon rod is coated with a back reflection film. The heat shield provided by the invention obviously reduces the heat loss, and has the advantages that the heat stress of the silicon rod is low, the core melting and rod cracking probability of the silicon rod is low, the temperature field is uniform, the large-diameter silicon rod can be beneficially obtained, the yield is high, the equipment is easy to manufacture, convenient to operate and simple to maintain, etc.