The Underground Direct Measurement Device for Coal Mine Methane Concentration is a new-generation methane concentration measurement system developed in accordance with the on-site testing requirements of the *Coal Mine Safety Regulations* and the *Detailed Rules for the Prevention and Control of Coal and Gas Outbursts*. As China’s first-of-its-kind high-precision in-situ underground detection device, it is primarily designed for the accurate measurement of methane concentrations in high-methane mines, mines prone to outbursts, and mines where rock bursts and coal and gas outbursts occur concurrently. This equipment offers three key advantages. First, the device utilizes a high-pressure-retaining tank and an underground compressed air power source to crush coal samples on-site via a mechanical rotation mechanism. Combined with a high-sensitivity, high-precision load cell that directly measures weight to calculate desorption volume, it completely resolves industry pain points such as gas leakage from sample tanks, manual reading errors, and the accuracy limitations of gas flow sensors; Second, it incorporates an intelligent data processing model that rapidly calculates gas content and generates real-time result reports. It also supports full-process video recording of the testing procedure and on-site digital signatures, ensuring dual traceability of both test data and the testing process. Third, it features a mobile terminal interface that facilitates both convenient on-site operation underground and remote data management above ground. This enables real-time upload of test data and intelligent alerts for abnormal conditions, comprehensively enhancing the efficiency, accuracy, and standardized management of gas content testing.