Pneumatic control gate valve

The utility model discloses a pneumatic control gate valve which comprises a valve body, a transverse flow channel is arranged in the valve body, a buttress is fixed in the valve body, a groove is formed in the buttress, a supporting plate is arranged in the groove, a through hole is formed in the supporting plate, a gate plate is arranged above the buttress, and a first inserting hole connected to the supporting plate in an inserted mode is formed in the gate plate. A first hard sealing alloy layer is arranged on the bottom face of the gate plate, a second hard sealing alloy layer matched with the first hard sealing alloy layer is arranged on the top face of the buttress, the bottom face of the gate plate is lower than the bottom face of the through hole, a valve rod is fixed to the top end of the gate plate, and a second inserting hole is formed in the first inserting hole. Insertion rods inserted into the second insertion holes are fixed to the top ends of the supporting plates. The gate valve can be opene