To study the predictive methods for simulating thermal flow fields prior to large-scale structural testing, a typical full-scale missile structure was utilized as the subject for modeling and computational analyses of the radiation heat field of whole missile. A specialized method for extracting modeling parameters and retrieving temperature zone information for full-scale missile structures was proposed. Additionally, considering the coupling effect of irradiation between heat zones near the section mating area of typical missile structures, a criterion for irradiation in cylindrical/conical temperature zones near the section splicing areas was established. Simulations of thermal flow distribution during thermal testing of typical full-scale missile structure were carried out, heat flux considered the coupling irradiation and not was computed, the results shows that the deviation of the heat flux calculation between those two could reach up to 70%, which indicates that it is imperative to consider the influence of coupling irradiant in temperature zones near the docking area during radiation heat flux calculations.