Steven tests for two explosives PBX-2 and PBX-1 were made by using a steel projectile of 2.0 kg. The pressure change was measured by pressure gauges,and ignition delay time was estimated and analyzed by high-speed motion pictures. The reaction overpressure of two explosives were gained by blast pressure gauges. The results show that the threshold velocities of ignition for explosives PBX-1 and PBX-2 range from about 35.0-35.5 m·s^-１ and 40-46 m·s^-１ respectively,and the ignition delay time of PBX-1 explosive is smaller than that of PBX-2 explosive remarkably,which demonstrates that PBX-1 explosive is more sensitive than PBX-2 explosive.