VOCs gas analyzer is using high temperature method, there is a heating chamber inside for analytic gas path. By adopting air bath heating method, it can make chromatographic column and gas paths before of after it in high temperature condition. VOC gas analyzer is using FID principle to analysis. This technology is a gas separation technology that multi component gas mixture pass through special chemical fillings of chromatographic column, then effectively separated while flow out of the column. FID technology is one of the effective methods for detecting organic gas of low concentration. After been separated from the column, the gas continuously delivered into the FID detector by the carrier gas. Under high temperature ionization of FID detector hydrogen flame, the gas molecular bond is opened and release the free ions and electrons. Under high voltage electric field of FID detector release electrons move to one electrode of the electric field, and generate signal current from the measurement circuit which is related to the quantity of gas components into the detector.