Pressure gas pipeline flange joint

The invention discloses a pressure gas pipeline flange joint which comprises a first flange plate and a nut. The front end of the first flange plate is connected with a first connecting pipeline, bolts are circumferentially distributed at the front end of the first flange plate, and the bolts penetrate through the inner side of the second flange plate and are in threaded fit with the nuts; by arranging the sealing buffer mechanism, in the locking process of the first flange plate and the second flange plate, the first sealing plates are in contact, extruded and attached, the first sealing plates are pressed more and more tightly, and the pressure and deformation force received by the first diaphragm spring and the second diaphragm spring are enhanced; and then springs generated by the first diaphragm spring and the second diaphragm spring can reversely push the first sealing discs, so that the two sets of first sealing discs are tightly matched, the sealing performance is improved, and the phenomena of loosen