Pneumatic valve capable of achieving self-locking and clamping during closing

The pneumatic valve comprises a pneumatic device, a threaded push rod, a partition plate and a movable plate, the threaded push rod is installed on the pneumatic device in a penetrating mode, the partition plate is fixedly installed on the threaded push rod, and a pressure spring is fixedly installed in the pneumatic device. The lower end of the threaded push rod is rotationally installed on the movable plate, a push rod is fixedly installed below the movable plate, a flow limiting block is fixedly installed at the lower end of the push rod, a pull rope is fixedly installed on the push rod, and the tail end of the pull rope is fixedly installed on the pull rod. According to the closed self-locking clamping pneumatic valve, a pull rope is fixedly installed on a push rod, when a base body falls, the pull rope is driven by the push rod to pull a pull rod to move backwards through a fixed pulley and a rotating wheel, then the pull rod drives a clamping plate to move backwards, a connecting plate is pulled to star