The functional relationship between resistivity and thermal conductivity and temperature of gold tin solder strip material with the brand of Au₈₀Sn₂₀ were studied in the temperature range of 208-423 K， and its heat transfer effect in MCM module was evaluated. The resistivity at five temperature points and thermal conductivity at four temperature points of the material in 208 K to 423 K were tested，respectively. Based on the theoretical model， the functional relationship between the resistivity and thermal conductivity with temperature was established. Finally， the heat transfer ability of the material at high temperature was evaluated by using the numerical method of simulated thermal diffusion. The results show that the relationship between the thermal conductivity and the resistivity of the solder strip material at 208 K to 423 K is consistent with the test results after using the modified function model. As the boundary condition of the chip surface temperature increases from 208 ~ 423 K， the difference between the simulation results of the heat flux density obtained by using the variable temperature thermal conductivity model and the idealized constant thermal conductivity model gradually increases to 5.5%， To sum up， the relationship between thermal conductivity and resistivity of gold solder strip material conforms to the Smith-Palmer equation modified by Wiedemann-Franz law， and the temperature effect of thermal conductivity should be considered in the heat transfer design of the material.