Pumping well weighing type automatic metering device

The utility model relates to a pumping well weighing type automatic metering device, composed of a metering system and a drainage valve control system. The metering system is assembled by a head, an upper tank and a lower tank, wherein the upper tank and the lower tank are in connection by bolts through a flange, and the head and the upper tank are in connection by bolts through a flange to form a completely sealed space. Output liquid flows into a gas-liquid separation device through a liquid inlet; gas separated from the output liquid is discharged from a discharge port on an upper portion and is metered by a gas flowmeter. Liquid flows into a measuring tank from a liquid storage tank at the lower part of the gas-liquid separation device for weighing metering. The drainage valve control system is composed of a control case, a stepping motor, a ball screw rod, a hoisting hydraulic cylinder, a hydraulic pipeline, a hydraulic cylinder, a pull bar, a drainage valve plate, a fixed base, and a centralizing strip;