This research aims to study the variations and differences in the water conservation capacity of typical forest stands in the eastern Qilian Mountains, and provide scientific support for the enhancement and management of regional forest water conservation capacity. The study focuses on six types of forests in the Beishan National Forest Park, including pure spruce forests, pure birch forests, mixed spruce-birch forests, mixed spruce-poplar forests, mixed birch-poplar forests, and mixed birch-larch forests. Field measurements and weighing, indoor soaking, ring cutting method, and correlation analysis methods are adopted to determine and analyze the hydrological effects of the forest canopy, litter layer, and soil layer. Eight indicators including canopy interception rate (%), undecomposed layer thickness (cm), saturated hydraulic conductivity (mm/min), and soil water storage capacity (%) were selected through sensitivity analysis and correlation analysis, and entropy weights method and comprehensive index method were used to evaluate the water conservation capacity of forest land. Results indicate that the water conservation capacities of the forest canopy, litter layer, and soil layer in the six typical forest stands in the eastern Qilian Mountains were affected by the type of forest stand. (1) The interception capacity of canopy vegetation in different forest stand types is as follows: coniferous forest > broad-leaved forest, mixed forest>pure broad-leaved forest. (2) The thickness and storage of litter showed a consistent trend, with pure spruce forests (needleleaf pure forests) having an undecomposed layer > semi-decomposed layer, while other forest types (needle-broadleaf mixed forests, broadleaf mixed forests, and broadleaf pure forests) had an undecomposed layer < semi-decomposed layer. (3) The overall soil porosity and saturated hydraulic conductivity showed that the mixed forests are greater than pure forests, with needle-broadleaf mixed forests are better. (4) The comprehensive evaluation of the water conservation capacity of the six typical forest stands reveals that mixed spruce-birch forests (0.746) > mixed birch-larch forests (0.547) > mixed spruce-poplar forests (0.504) > mixed birch-poplar forests (0.480) > pure birch forests (0.467)>pure spruce forests (0.244). As a whole, needle-broadleaf mixed forests could be considered as the target forest stand for regional forest structure adjustment and new forest establishment, especially mixed spruce-birch forests and mixed birch-larch forests were preferred. Directly establishing pure spruce forests should be avoided during creating new forests.