The computation methods for the coupled heat transfer and transient wall temperature of composite walled rocket nozzle were studied.While the stable ablative calculation for C/Cthroat insert was considered

the Enclosure-Radiative Heat Flux model was established to compute the radiative heat transfer in the nozzle

thus improving the calculation method of radiative heat transfer.The time-dependent variations of wall temperature for two composite walled nozzles were computed

and also compared with the results in the literature.The research shows that

the radiative heat transfer is stronger than the convective heat transfer in the entrance section of the nozzle;the Enclosure-Radiative Heat Flux model could compute more precisely the radiative heat transfer of the rocket nozzle.