ABSTRACT The retorting pyrolysis zone of underground coal gasification directly affects syngas quality. However, current research suffers from an unclear pyrolysis mechanism and blind control strategies. Using coal samples from the Hancheng Magouqu Mine, thermogravimetric and fixed-bed experiments were conducted to analyze the evolution of pyrolysis products and to clarify the pyrolysis mechanism. Finally, rational control conditions were proposed based on different gasification processes.