Magnesium alloy metal mold low-pressure casting molding cavity

The invention relates to the technical field of casting equipment, in particular to a magnesium alloy metal mold low-pressure casting molding cavity which comprises an upper casting mold and a lower casting mold, a forming cavity is formed in the lower end of the upper casting mold, the upper end of the lower casting mold protrudes outwards, a smelting furnace is fixedly connected to the lower end of the lower casting mold, and a liquid guide pipe is fixedly connected to the interior of the upper end of the lower casting mold. A pushing mechanism is arranged in the storage tank, cut burrs are pushed into the connecting pipe through the pushing mechanism, and the other end of the second pull rope is fixedly connected with the annular cutting knife; after a casting upper die is lifted through a hydraulic cylinder, extrusion on a plurality of sets of T-shaped pressing rods is cancelled, the T-shaped pressing rods are popped out and drive a take-up mechanism to move, a first pull rope is pulled through movement o