Abstract: The light interference methane sensor has many advantages, such as high accuracy, wide measurement range, good stability, high reliability and long calibration period. Some influence factors were studied which affected the gas refractive index of light interference methane sensor, such as temperature and pressure, etc. The sensor calibration principle with the pressure method was introduced, and the characteristic curve of the sensor was obtained by the corresponding experiment. Moreover, the nonlinear compensation algorithm was designed which is suitable for the light interference methane sensor, the experiment result was good.