Abstract: This paper summarized the research status of the influence of water on coal pore structure and spontaneous combustion characteristics in recent years, and analyzed the effects of water on coal pore structure, oxidation and heat release. Studies have shown that moisture has a dual effect on coal spontaneous combustion. The promotion effect is mainly manifested in the increase of water pore structure, the increase of hydroxyl groups, carboxylic acids and other groups which are easy to react with oxygen, and the reduction of the structure of the C-H group in the benzene ring to inhibit the coal-oxygen reaction, thereby the coal-oxygen composite reaction were strengthened. The inhibition is mainly reflected in the moisture occupied by the inner surface of the coal, the water film produced on the surface of the coal and the vapor pressure during the heating process to block the contact between coal and oxygen. In response to the limitations of current research, it is suggested that the study on the expansion mechanism of water on pore structure of coal should be strengthened, and the evaluation criteria and evaluation indexes of the degree of influence of different water content on coal spontaneous combustion should be established. The stage division and critical water content range of different water content on promoting or inhibiting coal spontaneous combustion should be obtained.