Gas pressure measuring device

The utility model discloses a gas pressure measuring device, which comprises a steel tank, a gas-vapor separation device and a pressure measuring device. The steel tank receives mixture of gas and water vapor in a measurement environment through a gas inlet and stores the mixture; the gas-vapor separation device is connected with a gas outlet on the upper part of the steel tank and is used for separating the gas and the vapor in the mixture output by the steel tank; and the pressure measuring device is used for measuring the pressure of the gas output by the gas-vapor so as to obtain the gas pressure after gas-vapor separation. Since the pressure can be generated in the steel tank after the gas-vapor mixture passes through the steel tank and the gas-vapor separation device and the pressure value can be displayed in the pressure measuring device, the actual value of the gas pressure of a coal seam can be measured.