Abstract: To study ignition mechanism of explosive under low velocity, code of LS-DYNA and Visco-SCRAM model were taken as numerical simulation on ballistic impact chamber test. The ignition reaction was attained at the initial velocity of 5.35 m/s which was consistent with test results from literature. The results show that the bulk rise of temperature wasn't mechanism of explosive ignition, but hot spots from cracks frictional were mechanism of ignition. The results provide new basis and support for non-shock ignition of explosive under low impact.