To study the mechanical properties of a new material with the change in temperature during the flight, a bending test is conducted in different temperatures. The result of the test indicates that in the same temperature, the mechanical properties of the material in the temperature rising period is apparently different compared with it in the cooling down period. According to test result, the relation between tensile modulus and bending modulus of the material is gained by the FEM analysis and the data is used for the FEM analysis of the new thermal-protection structure.