Abstract: With the increase of temperature in coal seam, the pore structure of coal will change, which will directly affect the characteristics of water imbibition and migration in coal. In this paper, considering the occurrence temperature environment of deep coal seam, the spontaneous imbibition test of coal at different temperature conditions was carried out with the help of nuclear magnetic resonance testing instrument, and the dynamic imbibition law of micro pore structure was quantitatively analyzed. The results show that higher temperature conditions (55 ℃ and 65 ℃) can increase the pore volume in the range of 0.001 μm to 0.1 μm, and decrease the pore volume in the range of 0.16 μm to 1.60 μm. The increase of temperature leads to the expansion of coal matrix, the decrease of pore size, the increase of the number of adsorption pores and the increase of imbibition equilibrium time. With the increase of temperature, the fractal dimensions of adsorption pores, seepage pores and cracks showed a trend of decreasing first and then increasing, increasing continuously, and increasing first and then decreasing, respectively. In the whole imbibition process, the adsorption hole is dominant, and the water absorption rate of the seepage hole decreases with the increase of temperature. The imbibition distance show multi-slope characteristics on the time scale, and the change rate of imbibition distance increases first and then decreases with the increase of temperature.