The non-shock ignition of explosives can bring huge accidental disasters, so it is meaningful to study the conditions under which explosives ignite. The safety performance of JHL-3, a polymer-bonded explosive (PBX), under low amplitude and long pulse load has been analyzed based on experiment and simulation from a macro perspective, and the load criterion for ignition of JHL-3 is given. First, JHL-3 was loaded under confining pressure by the modified separated Hopkinson pressure bar. By observing whether the explosives ignite at different pulses whose width and amplitude can be changed by changing the length and initial speed of the striker, we find that the greater the loading pressure, the shorter the loading time required for the ignition of JHL-3. According to the experimental results, the relationship between the amplitude and width of the loading pulse at which the JHL-3 is ignited is fitted. Then, load JHL-3 of different densities under the same conditions to analyze the influence of density on the ignition sensitivity of JHL-3. The experimental results show that the sensitivity is highest when the density is between 1.7-1.75 g/cm(3). Finally, based on the Uintah Computational Framework (UCF), the experiment is simulated by the coupling algorithm (MPMICE) of material point method (MPM) and implicit continuous-fluid Eulerian (ICE). JHL-3 is modeled by the Visco-Scram model, and the WSB model is used as a reaction model to simulate the combustion behavior of the explosive after ignition. The simulation results closely match the experimental results, further verifying the accuracy of the ignition criterion. The ignition criterion can predict the ignition of explosives under non-shock loading conditions, which has a guiding effect on the storage, transportation, and packaging of explosives.