<p>In underground engineering, ensuring the long-term stability of water-resisting coal pillars and coal pillar dams in the mine water environment is crucial. Therefore, it is necessary to gain an in-depth understanding of how the immersion height and chemical corrosion of mine water affect the mechanical properties of coal. This study subjected coal samples to saturation treatment with different mine water and different immersion heights. The failure characteristics of the coal were studied through acoustic emission (AE). The water distribution differences of the coal were obtained by nuclear magnetic resonance (NMR), and the corrosive effect of mine water on coal was analyzed by energy dispersive spectroscopy (EDS). The results show that S-series coal samples have higher moisture content, and acidic mine water significantly weakens the peak strength of coal, while alkaline mine water exerts a strengthening effect. The AE signal fluctuations of S-series coal samples are gentler, and all coal samples generate larger energy events near the immersion height line. Under low immersion height, the permeability of mine water in coal follows the order: acidic &gt; alkaline &gt; neutral. Meanwhile, acidic mine water dissolves carbonate minerals through chemical corrosion effect, neutral mine water mainly undergoes hydration, while alkaline mine water can undergo precipitation reactions. Finally, From the perspectives of macro-mechanics and molecular dynamics, the mechanism of action of immersion height and hydro-chemical corrosion on coal is analyzed. The research results provide new insights into the interaction between water and coal-rock, and further improve the understanding of the deterioration mechanism of coal pillars caused by mine water in practical engineering.</p>