Drought, as a natural phenomenon of abnormal regional water shortage, has a profound impact on the ecological environment. As the global climate changes and the frequency of abnormal climate events increases, the form of drought in my country will become increasingly severe in the future. The degree of forest canopy closure, forest density, tree species composition and age composition in this study area are extremely unreasonable, the structure and function of the plantation are single and the stability is poor, and problems such as pests, pests and rodents continue to appear. Due to the lack of tending management, the unadjusted structure of the initial timber forest has led to its low comprehensive ecological function. In order to ensure the long-term and stable ecological function of the forest, it is urgent to evaluate its water conservation function and regulate and manage it. This paper combines the fuzzy matter-element model and establishes an evaluation system consisting of 16 indicators including forest evapotranspiration, forest canopy water retention characteristics, soil physical properties, water retention characteristics, litter physical properties, and water retention characteristics. Evaluate the weight of different indicators and evaluate the water conservation capacity. In this paper, 6 different forest types in the Targou, Datong County, Qinghai Province, spruce×birch mixed forest (YB), spruce×green poplar mixed forest (YQ), spruce×larch mixed forest (YL), spruce Pure forest (Y), pure larch forest (L), and pure poplar forest (Q) are the research objects to quantitatively evaluate their water conservation capacity. The results show that the order of European closeness is YB (0.794) > YQ (0.723) > YL (0.655) > Y (0.494) > L (0.416) > Q (0.270). The greater the European closeness, the water source of this forest stand type. Stronger ability to conserve. Among the six forest types, the birch×poplar mixed forest has the strongest water conservation capacity, and the Qing poplar forest has the worst water conservation capacity. By assessing the water conservation capacity of forests, exploring the water balance of the basin, and paying attention to the hydrological effects of forests, it is of great significance for regulating the runoff of the basin and improving the local microclimate. In this paper, the fuzzy matter-element model is used to analyze and study the water conservation capacity of different forest types of plantations, and provide a scientific reference for the selection of local afforestation tree species, the improvement of forest water conservation capacity, the transformation of inefficient forests and the adjustment of stand structure.