To investigate the response characteristic of PBX-2 explosive under projectile impact at ambient temperature and 75 ℃, the projectile impact tests of PBX-2 explosive were conducted by a high temperature impact test device. The reaction overpressure of the explosive was measured by the shock-wave overpressure sensor and the response characteristics of the explosive at ambient temperature and 75 ℃ were comprehensively analyzed using recovered samples. The stress variation of PBX-2 at ambient temperature and 75 ℃ at different impact velocities was calculated and analyzed using finite element program LS-DYNA. The results show that the threshold velocity of ignition reaction for PBX-2 explosive at ambient temperature is from 263.5 m·s^-1 to 269.9 m·s^-1, while the threshold velocity of ignition reaction for PBX-2 heated to 75 ℃ is from 316 m·s^-1 to 367 m·s^-1. Compared with ambient temperature state, when the projectile velocity is less than 800 m·s^-1, the reaction degree of PBX-2 at 75 ℃ obviously decreases. However, when the projectile velocity is higher than 800 m·s^-1, the impact pressure of about 1.54 GPa can make the PBX-2 at 75 ℃ occur violent reaction.