Based on the InVEST model, the spatial-temporal distribution characteristics of water conservation in the Taizi River Basin from 2000 to 2020 were explored, and the land use change and landscape pattern evolution during the study period were quantitatively evaluated. Using Pearson correlation analysis and geographical weighted regression model, the relationship between landscape pattern and water conservation was analyzed. The results show that, at the landscape level, the amount of water conservation increases with the largest patch index, contagion index, and aggregation index; at the landscape type level, the capacity of water conservation gets higher when the cultivated land has larger area, higher patch density, and higher degree of landscape fragmentation, the forest land has higher dominance degree, and the construction land has smaller number and lower density of patches, with landscape being more fragmented. Spatially, the landscape contagion index plays a positive role in water conservation in most area of the basin, the number and density of patches in cultivated land have positive effect on water conservation in the southern central part and the northwestern part of the basin, respectively. The percentage of landscape of forest land has a positive effect on water conservation in the whole region, while the number and density of patches and percentage of landscape of construction land mainly play a negative role in water conservation.