The invention discloses a drilling hole stuffing device for drilling hole blasting. The device comprises a grain formed by filling an expanding agent in a packing cylinder produced by sponge and a kraft paper with a water penetration hole; the expanding agent is mixed by oversintered CaO, NaHCO3, quartz sand, clay, a polymer absorbent material and anhydrous ethanol; the grain is fixed on an axial expansion restraint mechanism consisting of a lead screw and a plug cover, and is closed in space formed by en elastic protective cover and the plug cover; and the elastic protective cover is locally provided with a heat absorbing pad and a thermal insulation pad. Through three technical measures of absorbing CaO and heat discharged by a water reaction by a NaHCO3 reaction, absorbing the heat again by the heat absorbing pad and insulating remained heat by the thermal insulation pad, the device enables the temperature of an explosion propagation device shielded by the thermal insulation pad to be lower than the tolerable temperature to guarantee safe operation of an explosion propagation system without misfire accidents; the expanding agent is limited by axial expansion in the reaction process, and is developed in the radial direction to increase the radial expansion pressure; and the grain and the inner wall of the a drilling hole are fully bridged to improve the stuffing quality and effect.