Abstract: Using steady state heat flow method composed of pulley reinforcement mechanism and hydraulic booster mechanism of two grade reinforcement mechanism loading to study the thermal contact conductance(TCC) efficient of AZ91D magnesium alloy and H13 die steel interface by the self-made measuring device, and the effects of interfacial load and temperature on TCC efficient were analyzed. The results show that, when the interfacial load was low, the TCC efficient changed significantly with the increase of the load. In the high load area, the sensitivity of TCC efficient on load declined. The higher the interfacial temperature, the more the TCC, in the temperature range of 320-370 ℃, the TCC coefficient changed little with the increase of the temperature, beyond this stage, TCC increased again with the increase of the temperature.