The invention relates to a calibration method and a calibration device and a method and a device for measuring equivalent ratio of combustible gas to oxidant, in particular to a calibration method and a calibration device based on laser induced plasma spectroscopy and a method and a device for measuring equivalent ratio of combustible gas to oxidant, aiming at improving the calibration accuracy of the existing calibration method, improving the measuring accuracy of the equivalent ratio of fuel to oxidant in the existing combustion system and improving the convenience in measurement of equivalent ratio of mixed fuel gas. Since plasma fluorescence signal intensity is high, the signal-to-noise ratio is high and the response sensitivity of an ICCD (intensified charge coupled device) which is used as light signal receiving equipment in a spectrograph is high, the measuring accuracy of the method provided by the invention is higher than the measuring accuracy of other existing equivalent ratio measuring method. Since the method is a non-contact measuring method, laser beam and fluorescence signal receiving equipment are not limited by spatial positions and the signals are convenient and rapid to process at a later stage, the method can satisfy the requirement on real-time online measurement. The technical scheme is suitable for the calibration method and the calibration device based on laser induced plasma spectroscopy and the measurement of equivalent ratio of combustible gas to oxidant.