Abstract: In order to solve the problem that the natural diffusion of gas in the negative pressure extraction pipeline to the gas chamber is difficult and need to filter water and dust effectively in the process of underground coal mine gas extraction, and the negative pressure change of the extraction pipeline will also affect the measured data of the infrared methane sensor, a new type of special gas path device is studied to connect the sensor gas chamber with the extraction pipeline, and the infrared detection sensing element and pressure acquisition element are built in the gas chamber to collect the gas concentration and pressure data and establish the pressure compensation algorithm model to correct the measured value of gas concentration. The results show that the gas path device of the sensor can realize the natural diffusion of the gas in the negative pressure extraction pipeline to the gas chamber, and the pressure compensation algorithm model can eliminate the influence of the negative pressure in the extraction pipeline on the gas concentration measurement.