Abstract: To explore the effects of different mixing ratios on the water conservation function of Cunninghamia lanceolata×Schima superba×Sassafras tzumu mixed forestsand to provide a scientific basis for optimizing the configuration of conifer–broadleaf mixed forests, three types of mixed forests with different mixing ratios (5 Cunninghamia lanceolata ×1 Schima superba ×4 Sassafras tzumu, 5 Cunninghamia lanceolata ×2 Schima superba ×3 Sassafras tzumu, 5 Cunninghamia lanceolata ×3 Schima superba ×2 Sassafras tzumu) were selected, with a pure Cunninghamia lanceolata plantation used as the control (CK). The stratified cutting method, quadrat harvesting method, and cutting ring method were employed to measure the water-holding capacity of the arbor layer, understory vegetation layer, litter layer, and 0-60 cm soil layer, and to compare the total water-holding capacity among different stands.The results showed that the water-holding capacities of different layers varied significantly among stands with different mixing ratios. The soil layer served as the main water storage component, accounting for more than 98% of the total water storage. In the mixed forests, the canopy, understory vegetation, and litter layers all had higher water-holding capacities than those of the pure stand. The total water-holding capacity of the stands followed the order: 5 Cunninghamia lanceolata ×3 Schima superba ×2 Sassafras tzumu (3231.89 t·hm⁻²)>5 Cunninghamia lanceolata ×2 Schima superba ×3 Sassafras tzumu (3186.36 t·hm⁻²)>pure Cunninghamia lanceolata forest (3024.22 t·hm⁻²)>5 Cunninghamia lanceolata ×1 Schima superba ×4 Sassafras tzumu (2935.40 t·hm⁻²).Correlation analysis indicated that forest water conservation function was significantly positively correlated with total aboveground biomass (P<0.05) but weakly correlated with average tree height and diameter at breast height, suggesting that biomass is a key structural factor influencing water-holding capacity. Mixing Cunninghamia lanceolata with Schima superba and Sassafras tzumu can significantly enhance the water conservation capacity of plantations. Appropriately increasing the proportion of broadleaf species is beneficial for soil water retention and hydrological regulation, with the 5 Cunninghamia lanceolata ×3 Schima superba ×2 Sassafras tzumu mixed model showing the best overall water conservation performance.