KJ751 Coal-mine Gas Drainage Pipeline Monitoring System is a smart gas drainage system supporting accurate gas flow metering, automatic gas drainage evaluation and big data analysis. Its online metering equipment independently developed with leading-edge circulating self-excited flow detection technology, ultrasonic flow detection technology, and laser gas detection technology enables real-time monitoring of gas density, flow, temperature, pressure, carbon monoxide content and other parameters at drill site (hole), evaluation unit, branch pipes, truck main, main pine, and the main pipe in the pump station. Based on the big data analysis of hole sealing quality, gas emission characteristics, extraction equipment fault diagnosis, etc., it can give abnormality alarms in a timely manner with optimal solutions. Relying an integrated gas drainage effect evaluation system, drainage measurement, evaluation unit division, drainage effect evaluation and optimal allocation of gas resource are included in a dynamic and transparent management, which provides basis for coal mine gas drainage evaluation, greatly improving the smart management of coal mines.