Fuxian lake basin is an important ecological barrier in the southwest of China and the Pearl River basin, but in recent years, the lake water level has been lower than the legal minimum water level. By integrating multi-source data, including meteorological, land use, and soil data, this study quantifies the water yield of the basin from 1990 to 2022 based on the Annual Water Yield module of the InVEST model, assessing the temporal and spatial characteristics of the water yield and exploring the contributions of precipitation and land use/land cover changes to the water yield through scenario analysis. The results indicate that the average annual water yield of Fuxian lake basin over the past 33 years is 265 million m3, showing a non-significant decreasing trend (z = -0.04, p > 0.05), with an average annual decline rate of 2.3 million m3 per year. The water-producing area is primarily located in the mountainous areas in the northern and western parts of the Fuxian Lake and the northern dam area. The contribution of precipitation and land use/land cover changes to water yield services in the basin from 1990 to 2020 is 73.08% and 26.92%, respectively. Among them, precipitation change is the main factor affecting the water yield services of the basin, and its contribution in each period is more than 70%. The results show that the complex relationship among precipitation change, land management and water yield services should be considered comprehensively in the formulation of water resources management strategy in the Fuxian lake basin.