Abstract: In order to determine the spontaneous combustion and thermal characteristics of hydrated coal during saturation to air drying, the combined experimental method of TG-DSC was adopted to research the thermodynamic parameters, activation energy and spontaneous combustion phase of coal samples with different moisture contents during air-drying of hydrated coal. The results show that the oxidation kinetic parameters of the hydrated coal during air-drying generally have a tendency of decreasing-increasing-decreasing at low temperature, but the influence of air-drying degree after reaching high temperature is not significant; the particle size of hydrated coal decreases, oxygen uptake and heat release increase, characteristic temperature and activation energy decrease, and spontaneous combustion period is shortened; in the process of drainage, spontaneous combustion period reduced to a smaller value and then increased, and the minimum value of spontaneous combustion period exists in the water content of 13.01%-14.87%. In the process of safety drainage of coal mine goaf, the degree of drainage should be reasonably determined according to the actual fire prevention arrangement and mining situation, so as to ensure that the residual coal will not develop into spontaneous fire due to excessive water drying.