There is a recognized need for cleaning the disposal of food scraps to maximize waste-to-energy conversion. The principal objective of this investigation was to carry out an in-depth analysis of the pyrolysis of Chinese cabbage scraps from the perspective of chemical group composition. First, a modified separation method for chemical group composition from feedstock was established, and the physicochemical properties had proved the bioenergy potential of Chinese cabbage scraps. Then, thermal decomposition and typical functional groups' release characteristics were determined using a thermogravimetric Fourier transform infrared spectrometer. The results showed that the pyrolysis behaviors of different extractives were not the same and the pyrolysis process of Chinese cabbage scraps can be divided into five stages. The release characteristics of typical gaseous products and functional groups of Chinese cabbage scraps and their extractives were roughly consistent with the pyrolysis temperature interval. Finally, the specific pyrolytic volatiles information was detected and analyzed by pyrolyzer-gas chromatography/mass spectrometry, which can be summarized as hydrocarbons, nitrogen-containing compounds, and oxygen-containing compounds. Furthermore, the possible formation pathway of different types of compounds was also inferred.