Pipeline gas self-closing valve

The utility model discloses a pipeline gas self-closing valve which comprises a self-closing valve body, a pressure relief seat is fixedly installed at the bottom of the self-closing valve body, a pressure relief cavity is formed in the pressure relief seat, a communicating pipe is fixedly installed at the top of the pressure relief seat, the top end of the communicating pipe extends into the self-closing valve body, and the bottom end of the communicating pipe extends into the pressure relief cavity. A movable seat is slidably mounted in the pressure relief cavity, the outer side wall of the movable seat is in sliding sealing contact with the inner side wall of the pressure relief cavity, and two stop levers are fixedly mounted on the inner wall of the top of the pressure relief cavity. The self-closing valve is reasonable in design and good in practicability, effective pressure relief protection can be automatically carried out on the interior of the self-closing valve body, the phenomenon that the self-clo