The thermal radiation properties of pyrolytic carbon(PyC)protective coatings for monocrystalline silicon furnace prepared by different processes were tested.The changes of normal emissivity of carbon materials caused by PyC protective coatings were discussed,and the influence of phase structure and surface appearance on the thermal radiation properties was investigated.The results show that the thermal radiation properties of PyC protective coatings with the wave band of 5-25μm are better than C/C substrate,further,normal spectral emissivity of CVD PyC coating remains basically at 0.85-0.90,and the normal total emissivity can reach0.89,which shows high thermal radiation performance.For resin PyC coating and CVD PyC coating,the degree of graphitization are 44.53%and 16.28%respectively,and the R value of Raman spectrum are 0.964and 1.384 respectively.Relatively disorder graphite structure of the latter causes various vibration modes,and the spectral emissivity is better,so the thermal radiation property of CVD PyC coating is excellent.A lot of spherical particles exists on the surface of the CVD PyC coating,and the more interface and spacing of particles reduce the number of particles per unit volume.Therefore,the scattering of thermal radiation is strongly strengthened,and the spectral emissivity is higher. The thermal radiation properties of pyrolytic carbon (PyC) protective coatings for monocrystalline silicon furnace prepared by different processes were tested. Changes of normal emissivity of carbon materials caused by PyC protective coatings were discussed, and the influence of phase structure and surface appearance on the thermal radiation properties was investigated. The results show that the thermal radiation properties of PyC protective coatings with the wave band of 5-25 μm are better than C / C substrate, further, normal spectral emissivity of CVD PyC coating remains basically at 0.85-0.90, and the normal total emissivity can reach 0.89, which shows high thermal radiation performance. For PyC coating and CVD PyC coating, the degree of graphitization are 44.53% and 16.28% respectively, and the R value of Raman spectrum are 0.964 and 1.384 . Relatively disorder graphite structure of the latter causes various vibration modes, and the spectral emissivity is better, so the thermal r adiation property of CVD PyC coating is excellent. A lot of spherical particles exists on the surface of the CVD PyC coating, and the more interface and spacing of particles reduce the number of particles per unit volume. Before, the scattering of thermal radiation is strongly. strengthened, and the spectral emissivity is higher.