Triaminotrinitrobenzene (TATB) is an important insensitive high explosive because of its low shock sensitivity and high energy. The evolution of shock into the detonation of TATB requires academic attention and research. A multi-points laser interferometer termed a photon Doppler velocimeter and a rotating mirror streak camera were used to study the shock initiation of detonation in a pressed solid explosive formulation, JBO-9021, which contained 85 wt.% TATB, 10 wt.% HMX and 5 wt.% Kel-F binder. In conventional experiments, the test explosive was assembled by using several columniform explosives with different external diameters. A new device was designed to solve complex problems. This device comprised a wedge-shaped explosive sample and a transparent window, and by using this device, the particle-velocity histories of eight shock positions and the shockwave velocity could be obtained. A series of shock-initiation experiments on high explosive JBO-9021 was performed, and the explosive samples were initiated at different intensity input shocks by an explosive-driven attenuator. The photon Doppler velocimeter was used to detail the growth from an input shock to detonation, and the increase in particle velocity in unreacted JBO-9021 was also obtained in low-intensity shock-initiation experiments. The shock velocity was measured with a rotating mirror streak camera in one experiment. Hugoniot data for JBO-9021 in the form of a shock velocity versus a particle velocity and the initial shock pressure versus a distance-to-detonation relationship (Pop-plot) were obtained. Based on the experimental results, the shock-sensitivity characteristic of JBO-9021 was described.