Gas drilling tool relief valve

The utility model relates to a decompression valve which is used for gas drilling tools in the low-pressure oil and gas field and comprises a decompression short-pitch 1, a decompression passage 2 and a decompression screw 3, wherein the decompression passage 2 is arranged on one side of the wall in the middle of the short-pitch 1, the decompression passage 2 is longitudinally and symmetrically arranged with a cross short-pitch vent groove 4 in the inner side with the method of turning milling, a label groove 5 which communicates vertically in the outer wall and the decompression screw 3, the decompression screw 3 is arranged with a radial screw groove 6 and is arranged with an axial screw groove 7 at the two sides symmetrically with the method of turning milling. With the dislocation and sealing theory, the simple and easy utility model can release pressure in the process of pulling out the drill and connecting single casing and thereby can facilitate the operation and shorten the working hour, meanwhile the