The utility model discloses a low-pressure-difference safety blasting device. Wherein the valve body is fixedly and hermetically connected with a pressure device; an inner pressure relief hole is formed in the valve body; wherein a valve cover is installed on the valve body in a threaded mode, an outer pressure relief hole is formed in the valve cover, a blasting pressure relief assembly is installed between the valve cover and the valve body through a fixing and clamping device, the blasting pressure relief assembly comprises an inner sealing ring, a reverse suction preventing baffle, a blasting piece and an outer sealing ring which are sequentially arranged, and a plurality of air holes are formed in the reverse suction preventing baffle. A pressure regulating needle is installed on thevalve deck in a threaded mode and provided with a needle body regulating part and a pricking piece needle head. When the pressure in the pressure cavity is larger than the external pressure, the rupture disk protrudes outwards and is directly punctured by the pressure regulating needle after protruding to a certain height, safe rupture is achieved, and the rupture pressure is accurate; the bulgingheight of the rupture disk is determined by the distance between the puncture needle head and the rupture disk, so that the rupture pressure is adjustable, and the rupture disk is suitable for low pressure difference.