Abstract: The high temperature environment has a great influence on the coal spontaneous combustion and the generation of index gas, thus affecting the early prediction of spontaneous combustion of coal. To solve the problem, based on the coal samples with nitrogen at 40 ℃, we simulated high temperature of mine environment, and made the point of 40 ℃ as the start of temperature programming experiment, analyzed the change laws of index gas, compared the experimental results of the normal coal sample to optimize index gas. The results show that the high temperature environment will make the characteristic temperature of coal decreased, concentration and growth rate of index gas increased significantly, which is more prone to natural oxidation; CO, C₂H₄, φ（CO）/φ（CO₂）, alkane ratio can be used as the main indicators of the early prediction of coal spontaneous combustion, and CH₄ and C₂H₆ can only be used as auxiliary prediction index.