Sediment transport from rivers to ocean is increasingly influenced by climate change and intensive human activities1, constituting a research priority of global relevance2. However, little attention has been paid to quantify and predict the contribution of driving factors to the sediment load. By integrating local-scale hydrologic modeling with soil erosion estimation model, and the soil erosion and sediment yield balance equation, we quantify watershed-scale changes in sediment load under forecasted climate change and human activities in the Yangtze River Basin (YRB), China. We also develop a new metric, the sediment load sensitivity index, that identifies sensitive to anthropogenic variability over the past 30 years. It was found that the reservoirs deposition was the primary factor (81.37 %) among human activities contributing to the decline in sediment load, followed by the soil and water conservation measures (SWCM) (18.63 %). The sediment load shows a slight increasing trend for the 1.5 °C and 2.0 °C global warming at 2020–2039 and 2040–2059, respectively. Climate change dominates the sediment load trend in the future due to the effectiveness of dams and reservoirs decreases and the saturation of the capacity of the SWCM to capture sediment. Although these findings indicate the importance of the impact of climate change on changes in sediment load, it is necessary to apply them to appropriate management to adapt to climate changes in future river basin management policies.