Based on the technique of magnetically driven ramp loading, the dynamic response of hydroxyl-terminated polybutadiene(HTPB) samples solidified by toluene diisocynate(TDI) were investigated under loading pressure up to 1.2 GPa. The velocity response curves of three HTPB samples with different thickness were obtained by Photonic Doppler Velocimeter(PDV). The sound velocity vs. particle velocity curve and stress vs. specific volume curve were obtained by Lagrange analysis method. Based on the relationships above and the loading history gained from experimental data, the experiments were validated by one dimensional hydrodynamic simulation. The simulation results are in good agreement with experimental results. Research shows that the Lagrange sound velocity vs. particle velocity behaves linear relationship. The loading strain rate ranges from 2×10⁵ s^-1 to 1×10⁶ s^-1 and the strain rate increases with the increasing of sample thickness, but no strain-rate effect is observed. All results agree with the shock loading results in reference.