The unsteady fully Navier-Stokes(N-S) equations were solved by Harten-Yee's TVD(total variation diminishing) and dual time march for the flow field.The 3-D unsteady heat conduction equation was solved for the structure.The coupling was processed as follows: the flow field acquired temperature's boundary condition from the structure and the temperature field of the structure acquired heat flux's boundary condition from flow at the fluid-solid interface.The method proposed here was validated by aerodynamically infinite column.The transformation of head of space shuttle's temperature was analyzed in detail during pneumatic heating process.The results show that the increase of wall temperature strongly affects heat flux.Therefore,solid-fluid coupled iteration is very necessary in the simulation since the influence of the increase of wall temperature can be considered.