An experimental device with an explosive-driven flyer plate was designed for shock initiation of the explosives at elevated temperatures. This device can heat up the acceptor explosives uniformly and keep the donor explosives out of the heating. Based on this device, the shock initiation tests were conducted for the HMX/TATB composite explosive heated to different temperatures: 14, 100, 140, 160 as well as 180 ℃, and the in-situ pressure histories were measured at various depths of the explosives. The ignition and growth reaction rate equation was used to numerically simulate the shock initiation of the explosive. Based on the experimental results, the parameters were determined for the ignition and growth reaction rate equation of the explosive shock initiation at different temperatures, the relationships were given between the model parameters and temperature, and the Pop relationships of the explosive at different temperatures were given. The results show that the shock sensitivity of the HMX/TATB composite explosive increases with an increase in the temperature, but its dependence on temperature is less than that of the HMX explosive in that the TATB explosive in the composite explosive has good desensitizing effect.