In this paper,one parameter called "equivalent thermal resistance" was raised to reflect insulation of
flexible thermal protection structure, and experiments were conducted to analyze the law between this parameter and
aerodynamic pressure on the surface of flexible thermal protection structure. The insulation property of flexible thermal
protection structure non linearly declines as aerodynamic pressure rises. So the effect of aerodynamic pressure on insu
lation property of flexible thermal protection structure should be taken into account in designing.