Online calibration method of in-situ type laser gas analyzer

The invention discloses an online calibration method of an in-situ type laser gas analyzer. A laser emitting unit, a laser splitting module, a signal detecting unit, a calibrating signal detecting unit, a signal switching module, a laser device controlling module, a signal processing module, a data analyzing module, a calibrating air chamber and a measuring pipe are provided. The online calibration method comprises the following steps that: during regular measurement, the signal detecting unit is connected with the signal processing module through the signal switching module so that the regular measurement is carried out on the in-situ type analyzer; and when calibration needs to be carried out, standard gas with known consistency is charged into the calibration air chamber firstly, the calibrating signal detecting unit is connected with the signal processing module through the signal switching module, and the signal processing module records a gas absorption spectrum obtained by the calibrating signal detecting unit and can be used for comparing a measurement value with a calibrating air consistency value, and thus the online calibration of the in-situ type laser gas analyzer is realized.