Exploring the water and sediment regime and its driving factors in the Xinjiang River Basin can provide a scientific basis for the prevention and control of soil erosion and the rational development and utilization of water and sediment resources in the basin. Based on the precipitation data of Yiyang Station in the Xinjiang River Basin and the runoff and sediment load data of Meigang Station from 1956 to 2019，this paper used multivariate statistical analysis methods to study the water and sediment dynamics in the basin and its response to rainfall and human activities. The results show that the annual precipitation and annual runoff in the Xinjiang River Basin showed a slight increasing trend from 1956 to 2019，but there was no obvious turning point. The annual sediment load shows a significant decreasing trend，and there was a sudden change in 1999. The sediment reduction rate after the sudden change reached more than 50%. After 1999，the measured cumulative sediment transport volume decreased by 32.309 1 million tons，with a reduction rate of 26.45%. Furthermore，after the mutation year，the average contribution rate of human activities to the reduction of sediment load in the Xinjiang River Basin exceeded 100%. Human activities (reservoir construction and large-scale water conservation project construction) played a decisive role in the change of sediment load and were the main reason for the reduction of sediment load in the Xinjiang River Basin. The research results can provide a reference for the rational development and utilization of water and sediment resources in the basin.