Several animal oils commonly used as lighting fuels in early ancient China include mutton tallow, beef tallow and lard. Of course, wax was also one of the ancient lighting fuels. It was not until the Wei, Jin and Southern and Northern Dynasties that the use of vegetable-oil lighting fuels in ancient China began to gradually increase. Affected by the natural conditions of various places, the varieties of oil crops suitable for planting in different regions of China are also different. Oil crops have certain regularity and stability in regional distribution, directly affecting the planting structure and oil consumption in most parts of China. The analysis of lighting fuels is one of the methods to research the oil used in the past and provides important reference for crop planting in ancient China. The lighting fuels used in ancient times were organic materials, not easy to preserve. Therefore, scientific analysis and understanding the trace organic residues is a big challenge. Nevertheless, Fourier transform infrared spectrometry (FTIR) and thermally assisted hydrolysis-methylation pyrolysis-gas chromatography/mass spectrometry (THM-Py-GC/MS) techniques have great advantages for the analysis of trace organic residues, and provide important technical support for the extraction and identification of unearthed organic mixtures. In this work, FTIR and THM-Py-GC/MS were used for the scientific analysis of trace organic residues in a porcelain lamp excavated from Tomb M8 in Xinzhou, Shanxi Province. Py-GC/MS were carried out with a pyrolyzer EGA/PY-3030D (Frontier Lab, Japan) attached to a GC/MS instrument (Agilent, America). The pyrolyzer furnace temperature was set at 600℃, and those of the injector and the interface were set at 280℃. The samples were held in the furnace for 6 s to achieve complete pyrolysis. The initial chromatographic temperature was 50℃ and held for 5 min, and the temperature was then increased at 10℃/min to 280℃ and held for 10 min. The carrier gas was helium, and the split ratio was 1∶5. The electron ionization voltage of the mass spectrometer was 70 eV. The temperatures of the ion source and the quadrupole were 230℃ and 150℃, respectively. The mass data was collected from 50 to 750 (m/z) with a scan time of 0.5 s. Tetramethylammonium hydroxide (TMAH) was used to convert the fatty acids and alcohols into homologous methyl esters and methyl ethers, respectively. The NIST17 Library was used to identify the compounds. The normalized areas were used to evaluate the peaks. The results show that the main components of the residue were saturated fatty acids, unsaturated fatty acids, fatty alcohols, hydrocarbons, etc. Azelaic acid—the marker in lamp-fueled drying oil, and cholesterol—the marker in lamp-fueled animal fat, were detected, respectively. In combination with the previous research results and comparison reference materials such as animal fat, plant oil and wax, it was found that the residue in the lamp was a mixture of linseed oil, mutton tallow and beewax. In the previous studies, the lighting fuel in a lamp mainly had one or two components, and cases of the simultaneous existence of three mixtures have not been reported. Py-GC/MS enables the analysis of trace organic residues. Also, the scientific analysis of porcelain lamp residues provides important information for the study of lighting fuels in northern Shanxi of ancient China.