Based on the relation of thermal conductivity and thermal resistance, the interface-resistance-baseed thermal conductivity model was established to predicet the PBX thermal conductivity. The interface-contained samples were prepared by coating fluorine rubber on the surface of TATB pill. The conductivitys of as-repared samples and TATB pills and fluorine rubbers pills were measured by using the flash diffusivity method. The coefficient of thermal conductivity of TATB/fluorine rubber layer are 6.18×10^-3, 6.53×10^-3, 9.87×10^-3, 2.16×10^-2, 7.72×10^-3 W·m^-1·K^-1, respectively at 293-333 K. The thermal conductivity of the TATB-based PBX was obtained by using the thermal condctivity model. The results of caculation were well agreed with the test value.