The Gushanchuan Basin of the Loess Plateau was selected as the study area. The interannual variation of flow-sediment relationship and the mutation year were analyzed using the Mann-Kendall and the Pettitt test. The results of the runoff and sediment yield of Gushanchuan showed a significant decrease trend (p<0.01) from 1965 to 2014, and the mutation year was 1979 and 1996, according to which the study period was divided into the reference period (1965-1979), the transition period (1980-1996), and the benefit period (1997-2014). Compared with the reference period, the average annual runoff depth and sediment modulus decreased by 34.11 mm and 401.48 t/km² in the transition period, respectively, and decreased by 65.05 mm and 213.09 t/km² in the benefit period. When the runoff depth was less than 10 mm, the flow-sediment relationship was discrete. When the runoff depth was more than 10 mm, the flow-sediment relationship was relatively stable. The contribution rates of human activities for runoff and sediment reduction during the transition period were 79.12% and 86.45%, and the contribution increased to 86.45% and 87.45% in benefit period, respectively.