The utility model relates to an optoacoustic spectroscopy principle transformer online monitoring system based on eliminate alternately influence, this system uses a special design's DBR laser instrument, the one end direct and air chamber is connected, the process of intermediate coupling has been saved, use model reference adaptive's method in the aspect of data acquisition, assign RFB neural network structure model as reference model, assign least square monobasic linear regression model as adjustable model, the relatively output of two models, regard the difference that reachs as the parameter of adjustable model, finally make controlled object's output trend towards reference model. The utility model discloses based on photoacoustic spectrometry, can furthest reduce the multicomponent gas alternately to gas data quantitative analysis's influence.