The experimental analyses of ignition and burning responses of mild-impacted granular explosive, namely, cyclotrimethylene trinitramine (RDX) and cyclotetramethylene tetranitramine (HMX), were performed based on an optimized drop-weight system equipped with a High-Speed Camera (HSC). It has been found that jetting phenomena observed by HSC is the result of the energy released by gaseous products, which push the pulverized or melted explosives to splash radially. Jetting is the only and the most obvious difference between reactive and inert particles prior to combustion so that it can be regarded as the sign of ignition more accurately than other ways. For RDX sample, the molten phase plays an important role in the hot-spots formation. After a piece of waxed paper is put on the glass anvil, the jetting of molten-phase RDX will be limited due to the high-roughness of waxed paper. Moreover, ignition growth to burning probability of RDX particles is increased compared with the non-waxed paper case. Radial deformation velocity, jetting velocity, and flame propagation velocity have been estimated via image processing, making it possible to quantify the violence of mechanical deformation and chemical reaction.