Abstract: Orifice plate flowmeter is widely used in coal mine gas extraction and measurement, but it has not been used correctly in many coal mines. In order to solve the problems caused by the use of orifice plate flowmeter in person or technical reasons, in this paper, through the analysis of the problems in the selection, installation, calculation and maintenance of the orifice palte flowmeter, the correct use requirements are clarified to guide the user to use correctly and to promote the accurate metering of orifice plate flowmeter in gas extraction.