Abstract: In order to solve the problem of large error in the detection result of optical interference methane detector in Ehuobulake Coal Mine.Through expounding the principle of optical interference methane detector, underground field test and laboratory contrast experiment in coal mine, this paper studies the influencing factors of errors in underground measurement of methane concentration and gives an correction model, and the correction model is verified on site.The research show that there is no problem in the quality of the underground optical interference methane detector, and will not cause the error of the measured value.The concentrations of CO, CO₂ and O₂ are the influencing factors of the measurement error, in which the concentration of O₂ is the main controlling factor.Atmospheric pressure, air temperature and humidity have little effect on the measurement error of optical interference methane detector.A correction model for the measurement results of the optical interference methane detector under the influence of three factors is proposed.Through field verification, the error difference between the corrected results and the gas chromatograph results is 0.01%-0.15%, and the corrected results are more accurate.