The rock property difference of bedded composite rock often does not lead to ideal Pre-splitting blasting effect. The influence factor of Pre-splitting such as the dynamite quantity and explosive structure was studied by experiment with transient dynamic strain gauge testing system. At the same time, the damaged rock reduced by blasting was examined with RS-STOIC ultrasonic gauge. The results indicate that different dynamite densities are taken for considering especially property of bedded composite rock. The conclusion for cite.