Abstract: Heat radiation is the primary way for the heat transfer between pressure tube and calandria tube of TACR,and its accurate analysis is very important for design and safety analysis of TACR.A calculation model of radiation heat transfer between the pressure tube and calandria tube of TACR,which is based on grey body radiation model and electronic network method,has been established.The cases with temperature boundary condition and heat flux boundary condition are discussed,and the results prove that this model can be applied to the analysis of radiation heat transfer between the pressure tube and calandria tube.