To address the challenges associated with forming frozen ground in permafrost mining areas, five concentrations of W-OH (0%, 1.5%, 2.5%, 3.5%, and 4.5%) were applied to the bottom of disturbed soil bodies to reform the waterproof layer at Muli mining area, Qinghai Provinve, China. Compressive tests, infiltration tests, and simulated rainfall tests were conducted to evaluate the reformed waterproof layer from three perspectives: physical performance, infiltration and sediment yield, and cost-effectiveness. Eight key factors influencing the reformed waterproof layer were identified using the analytic hierarchy process and expert scoring method, leading to the development of a functional evaluation system. The optimal scheme for the reformed waterproof layer was determined based on a comprehensive scoring approach. The results indicate: (1) W-OH enhanced the strength of coal gangue solidification, with the most significant improvement observed at 4.5% W-OH concentration. (2) Higher W-OH concentrations decreased the infiltration rate of the reconstructed aquiclude layer, extended the steady infiltration duration, and reduced cumulative infiltration. (3) Under rainfall conditions, increasing the W-OH concentration lowered the stable infiltration rate of coal gangue solidification, increased the average runoff rate, and elevated sediment yield. Besides, the average runoff rate and the average sediment yield are positively correlated with the concentration of W-OH and the slope gradient. (4) While the 4.5% W-OH concentration scheme achieved the highest comprehensive functional score, it posed practical challenges, such as clogging nozzles during application. Therefore, the 3.5% W-OH concentration scheme, which had the second-highest score, is recommended for practical implementation. These findings provide a theoretical basis for applying W-OH to reform waterproof layers over frozen ground in alpine mining areas.