Abstract: In the process of underground coal gasification, especially in the dry distillation zone, the organic substances generated by pyrolysis will cause potential pollution to the surrounding aquifers, which seriously restricts the industrialization of underground coal gasification. The coal samples were subjected to slow pyrolysis at different end temperatures from 200°C to 600°C. This experiment can simulate the pyrolysis reaction under the oxygen-free condition in the dry distillation zone of gasification channel distillation, and explore the variety and content of typical organic substances produced by coal pyrolysis. The results showed that the highest content of oxygenated compounds in the pyrolysis products was 36.19% at a pyrolysis temperature of 200°C, with the increase of temperature, the content changes slightly. The phenolic compounds increased with the increase of pyrolysis temperature, and the content reached 17.97% at 600°C. The content of aromatic hydrocarbon compounds in raw coal is relatively high. When the temperature is higher than 300°C, a large amount of aromatic hydrocarbon compounds begin to release. The proportion of aromatic hydrocarbon compounds in the total pyrolysis products is relatively high. A large amount of aliphatic hydrocarbon compounds were produced by pyrolysis at 300°C. With the temperature increasing, the content of aliphatic hydrocarbon compounds decreases continuously. At 600°C, the content of aliphatic hydrocarbon decreases to about 10% of the total products.