One-dimensional plate impact experiments have been performed to study the double shocks to detonation transition and Hugoniot state in the HMX-based explosive JOB-9003. The flyer was a combination of sapphire and Kel-F, which can pass two different pressure waves into PBX Explosive JOB-9003 sample after the impact. The particle velocities at interface and different depths in the JOB-9003 sample were measured with Al-based electromagnetic particle velocity gauge technique, thus obtaining particle velocity-time diagram. According to the diagram, the corresponding Hugoniot state can be determined based on the particle velocity and shock wave velocity in the sample. Comparing with sustained pulse experiments, PBX Explosive JOB-9003 shows desensitization feature due to the pre-pressed shock wave.