In order to explore the gas generation law during the oxidation process of long-flame coal and determine the appropriate early warning gas index of coal spontaneous combustion danger, the spontaneous combustion index gas generation law of long-flame coal in Yingpanhao Coal Mine in Ordos under five groups of air flow rate (50～150 mL/min) was systematically studied through the programmed temperature increase experiment (35～300 ℃ , heating rate 1 ℃/min). The results showed that there was a critical value of 125 mL/min for air flow. When the value is lower than, the production and oxygen consumption rate of CO, CO2, CH4, C2H6, C2H4 and other gases increase with the increase of flow. Above the value, the gas production decreases due to insufficient contact with oxygen owing to heat loss. According to the dynamic characteristics of the index gas, the oxidation process was divided into three stages: below 80 ℃ is the slow oxidation stage (the gas generation is very low); 80～160 ℃ is the accelerated oxidation stage (CO concentration increases significantly, oxygen consumption rate increases steadily); Above 160 ℃ is the stage of vigorous oxidation (sudden increase in hydrocarbon gases, a surge in oxygen consumption rate, marking irreversible cracking of coal). The key warning indicators showed that C2H4 appeared after 130 ℃, and CH4 increased suddenly at 160 ℃, marking the beginning of vigorous oxidation. The Graham coefficient (R2) of ＞2% (＞160 ℃) indicates that spontaneous combustion has entered a dangerous phase and requires urgent intervention; The CO/CO2 ratio plateaued after 210 ℃.   The influence of ventilation flow rate and temperature on the spontaneous combustion process of long-flame coal were revealed, and a theoretical basis for the early warning and prevention and control of spontaneous combustion of coal in mines was provided.