In this study a thermal design method based upon steady state conduction and radiation coupled heat transfer process is presented for multilayer thermal insulations. With the presented method the optimal number of re鄄 flecting foils and the thickness of each insulation layer could be obtained when the foil distribution characteristics in the multilayer thermal insulation was defined. Case studies for multilayer insulations thermal design under specified conditions were conducted. Results showed that the multilayer insulation designed with unvaried thickness in each in鄄 sulation layer had less mass than the multilayer insulation designed with unvaried temperature drop in each insulation layer. Results obtained in this study may be useful in the thermal design of high temperature multilayer insulations.