Abstract: Heat environment parameters of rocket motor were analyzed and computed based on structure and work condition of certain detector.Solid radiation heat flux of rocket motor was computed by finite element method,and thermal protection scheme was designed according to heat flux boundary condition.Multilayer insulation material performance was expressed by equivalent emissivity and temperature field was simulated.As the performance parameters are difficult to determine,the temperature field was computed in wide parameter range.Efficiency and reliability of thermal protection scheme were validated and primary influential factors to thermal protection performance were analyzed,providing a theoretical basis for design and selection of thermal protection scheme.