Abstract: Under certain conditions, macromolecules and non-volatile organic compounds follow certain cracking rules, that is, specific samples can produce characteristic cracking products and product distribution. Pyrolyzer-gas chromatograph- mass spectrometer (Py-GCMS) combines fast pyrolysis technology with gas chromatography-mass spectrometry technology, as an important instrument for the research of biomass fast pyrolysis products, which can be used for the qualitative and quantitative analysis of complex matrix components with low volatility. In this article CDS5200-7890A-5975C Py-GCMS was used as an example, starting from the principle of the instrument, the operation skills of Py-GCMS was introduced, and the requirement of Py test samples and operational precautions were explained in detail. The experience of instrument maintenance and troubleshooting were emphatically summarized and shared, and the orderly, safe, and efficient operation of Py-GCMS which not only guarantees scientific research activities, but also extends the service life of the instrument to a certain extent were pointed out.