Currently, the stable optical interference type methane detector performance, long life, but due to manual reading, the low degree of automation, before the test, in order to prevent the emergence of large temperature changes in pressure calibration zero drift, scale values and must be Location temperature measured close to the inlet Lane, pinch release methane suction ball cleaning chamber, then zeroing. This device is not intuitive readings, human error is large enough to hold the data. Based on this, the use of image analysis and information processing, is proposed as a photoelectric conversion element using CMOS noncontact measurement, CMOS output signal after analogdigital conversion become highspeed digital image data to achieve CMOS digital image data by the DSP collection, storage, and image data for interference analysis algorithms, and ultimately to achieve highprecision measurement of methane concentration.