Abstract: Hydraulic techniques employed in coal mines, including coal seam water infusion and hydraulic fracturing, introduce water into coal seams. The subsequent imbibition and migration of the retained water within the coal's pore-fracture system govern the final wetting state of the coal mass. Given coal's complex pore-fracture network, its micropores, mesopores, and macropores compete for the retained quantitative water. To investigate the migration behavior of quantitative water within the pore-fracture structure of bulk coal, an experimental study on its imbibition and migration was conducted. Utilizing low-field nuclear magnetic resonance (NMR) technology, the migration patterns of quantitative water within the micropores, mesopores, and macropores of bulk coal were tested and analyzed. The results demonstrate that: The migration of quantitative water in bulk coal exhibits two distinct stages. In the initial stage, the externally introduced water simultaneously enters both adsorption and seepage pores, resulting in a decrease in the free water signal and an increase in the adsorbed and bound water signals in the NMR data. During the second stage, water within the seepage pores progressively migrates into the adsorption pores driven by capillary forces, ultimately completing the transfer from seepage to adsorption pores. At the conclusion of imbibition, water wetting the adsorption pores constitutes 62% to 99% of the total, while water retained within seepage pores accounts for only 1% to 38%. The wetting rate per unit time of water within the pore-fracture structure of bulk coal shows a positive linear correlation with porosity. Well-developed pore throats enhance the coal wetting efficiency under the combined influence of capillary and gravitational forces. Conversely, the imbibition equilibrium time within the coal's pore-fracture structure exhibits a non-linear negative correlation with porosity, fitting the Boltzmann equation. By examining the imbibition and migration behavior of quantitative water in the pore-fracture structure of bulk coal, this research provides a comprehensive analysis of coal seam imbibition mechanisms and characteristic fluid migration patterns, thereby offering a theoretical foundation for optimizing hydraulic fracturing and coal seam water infusion strategies.