Abstract: In order to improve the accuracy of prediction and prediction of coal spontaneous combustion at working face of and avoid the deviation caused by human factors in the determination of coal spontaneous combustion index gas, taking fresh coal samples at 10310 working face of Xinglongzhuang Coal mine as the research object, 4 stages of coal spontaneous combustion and 13 possible index gas parameters of coal spontaneous combustion were obtained through temperature program experiment. Then, grey correlation analysis and Kendall's tau-b correlation coefficient theory are used to optimize the index gas of coal spontaneous combustion. The results showed that CO/CH₄ was the primary index in the initial stage, and CO/CO₂ and CO were the auxiliary indexes. CO/CO₂ was the primary index and C₂H₄/CO was the auxiliary index in the oxidation acceleration stage. CO/CO₂ was the primary index, and C₂H₄/C₃H₈ and C₃H₈/C₂H₆ were the auxiliary indexes. In the late intense oxidation stage, C₂H₄ is the primary index, C₃H₈, CO is the auxiliary index.