In recent decades, global climate has changed abnormally and extreme hydrological events have occurred frequently. It is of great significance to understand the dynamic changes of extreme sediment and explore its possible influencing factors for preventing sediment disasters. In this study, the Wuding river basin in the middle reaches of the Yellow River was taken as the research object. From the four aspects of magnitude, time, intensity and frequency, eight extreme sediment indexes were established, including annual maximum 1-day sediment concentration (Sx1d), annual maximum 5-days sediment concentration (Sx5d), occurrence date of annual maximum 1-day sediment concentration (DSx1d), occurrence date of annual maximum 5-days sediment concentration (DSx5d), average annual sediment concentration (Sint), high sediment concentration (S95p), extremely high sediment concentration (S99p), and days of hyperconcentrated flows (S200). Mann-Kendall trend test and circular statistical approach were used to analyze the variation trend and time distribution characteristics of extreme sediment indexes. The change-point of indexes was determined based on Pettitt test, and the range of variability approach was used to quantitatively evaluate variation of each index. Finally, the influence of rainfall erosivity and ecological construction measures on extreme sediment changes are discussed. The results showed that: (1) From 1958 to 2018, all extreme sediment indexes of Wuding river basin showed a significant decreasing trend (p<0.05). (2) The rush period of Sx1d was from June 30 to August 18, and the rush period of Sx5d was from July 11 to August 17, which was more concentrated than that of Sx1d. (3) S200 reached moderate alteration, Sx1d, Sx5d, Sint, S95p and S99p reached high alteration, and S95p and S99p had the largest alteration, with alteration of -100%. The overall change of extreme sediment indexes was 83.72%, which belonged to high alteration. (4) During 1963—1966 period, the decrease of rainfall erosivity led to a reduction of extreme sediment in the Wuding river basin to a certain extent. During 1982—2018 period, NDVI and annual cumulative value of dam control area (A_d) were significantly negatively correlated with extreme sediment indexes (p<0.05), and path analysis indicated A_d had a greater direct effect on extreme sediment indexes than NDVI, which was the main factor affecting the change of extreme sediment. The research results are helpful to enhance the understanding of extreme sediment changes in Wuding river basin, and provide a theoretical basis for formulating sediment disaster prevention strategies.