The method and device for methane air mass interface identification and adjustable range laser remote measurement of methane concentration of the present invention relate to the field of gas detection and analysis, and are composed of an STM32 controller, a laser drive circuit, a laser temperature control circuit, a photoelectric detection circuit, and a phase-locked demodulation circuit. , three-dimensional space laser measurement tracker and built-in wind speed sensor, the STM32 controller is respectively connected with the laser drive circuit, laser temperature control circuit, phase-locked demodulation circuit and three-dimensional space laser measurement tracker circuit; the photoelectric detection circuit and phase-locked demodulation Circuit connection. The invention has fast measurement speed, response time of ms level, high measurement sensitivity, reaching ppm level, maximum detection distance of 100 meters, and one-time detection of 30 meters long range, which improves detection efficiency; The high dust and strong corrosive gas environment under test has no effect on the measurement results; and the remote detection function enables the detection of places that cannot be reached or are difficult to reach.