The invention belongs to the technical field of coal mine safety, and particularly to a high negative pressure pipeline gas pumping and extracting metering device and a using method thereof. Accordingto the high negative pressure pipeline gas pumping and extracting metering method and device, a gas pumping and extracting pipe, a flow guiding pipe, a telescopic valve sleeve and a metering device body are included, and the metering device body is composed of a piping, a water storage tank and a gas meter. By utilizing the telescopic valve sleeve and simultaneously and slowly opening a gas inletand a gas outlet of the gas meter, the high negative pressure pipeline gas pumping and extracting metering device and the using method thereof can be used for measuring methane flow in a downhole high negative pressure gas pumping and extracting borehole and a pipeline and is suitable for a water-free drilling pipeline and a water drilling pipeline; and in measuring of gas flow through the high negative pressure pipeline gas pumping and extracting metering device, resistance of a pumping and extracting system is not increased but can be reduced, so that accurate measuring of the gas flow is achieved, accurate metering method and equipment are provided for gas pumping and extracting metering and coal seam gas outburst elimination evaluation, the promoting effect for safe mining of a coal mine is achieved, and the high negative pressure pipeline gas pumping and extracting metering device and the using method thereof can also be applied to flow measuring of other gases except methane indownhole and ground high negative pressure pipelines.