In order to study explosive safety under impact, the impact sensitivities of TNT, composition B, desensitizing RDX etc typical explosive cylinder were measured with the 400 kg drop hammer, and the results were comparatively analysized with form coventional impact sensitivity test (GJB772A-1997). The result show that the impact sensitivity of explosives with simliar composition is closely related to its compressive strength and molding process. Safety of TNT is best in TNT-based explosive, and impact sensitivity of HMX-based explosive is lower than that of RDX-based explosive.